Devices, systems and methods for treating pain with electrical stimulation

ABSTRACT

Devices, systems and methods are provided for treating migraine headaches and other conditions by non-invasive electrical stimulation of nerves and other tissue. A hand-held device includes a housing with a controller having a signal generator, an electrode for delivering electrical signals, and a conductive surface configured as a return path for the electrical signals. In certain implementations, the electrode is repositionable with respect to the housing. The patient can self-apply the hand-held device by pressing it against areas in need of pain relief. The device may include a pressure-sensitive gating switch to control delivery of the stimulation therapy. In certain embodiments, the electrode is a rollerball electrode. The device may include a chamber for retaining and dispensing conductive gel to the therapy site. In certain approaches, the device includes an electrode support for coupling an electrical stimulation system to the head for hands-free electrical stimulation therapy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/744,335, filed Jun. 19, 2015 and scheduled to issue as U.S. Pat. No.9,737,709 on Aug. 22, 2017, which is a continuation of U.S. applicationSer. No. 13/570,004, filed Aug. 8, 2012 and issued Jun. 23, 2015 as U.S.Pat. No. 9,061,148, which claims the benefit of priority under 35 U.S.C.§ 119(e) to U.S. Prov. App. No. 61/538,015, filed Sep. 22, 2011, andU.S. Prov. App. No. 61/658,756, filed Jun. 12, 2012. The disclosures ofall of the above-referenced prior applications, publications, andpatents are considered part of the disclosure of this application, andare incorporated by reference herein in their entirety.

BACKGROUND

Many people who go to the doctor for the treatment of headaches areexperiencing migraines, especially those with a history of minor neckinjury. In the United States, it is estimated that over 20 millionpeople suffer from migraines, which approximates the number of diabeticsand asthmatic patients combined. Migraines occur in over 15% of womenand over 5% of men. It has been estimated that direct and indirect costsof migraines in the United States exceeds $10B per year.

The occipital nerves tend to be an important part of the headachecircuit that occasionally causes migraines. The occipital nerves aremade up of a convergence of fibers from the first, second, and thirdcervical spinal nerves. These fibers form two sets of greater and lesseroccipital nerves which loop outwards to control the muscles andsensation at the base of the skull and the scalp. These nerves runapproximately one-half inch under the surface of the skin of a patient'shead, on the upper neck and scalp. FIG. 1A is a side view of a patient'shead 80 with paths 82 extending along the surface to depict theproximate locations under which the occipital nerves and branches 82 a-cextend. FIG. 1B is a rear view of the patient's head 80 with theexternal occipital protuberance 92 resected and lifted on the right side94. Various occipital nerve paths 90 are shown, including the greateroccipital nerve path 90 a and the lesser occipital nerve path 90 b.

A wide variety of medications are used to treat migraines, includinglong-activating preventative medications such as beta blockers andepisodic migraine-reversers, such as tryptophan pain medications. Insome cases, narcotics are used. However, many patients with migraines donot get satisfactory relief with medications. Some have tried the use ofbotulinum toxin (Botox) which may help relax the surrounding musculatureand improve migraine symptoms in some patients. However, Botox and othermedications are accompanied by a number of side effects that can beunpleasant to the patient.

In extreme cases, patients with intractable migraines historically haveundergone surgical removal of occipital nerves. While this procedure hasbeen known to provide transient relief (approximately 4-6 months), theheadaches usually return in a more severe form that is unresponsive toother treatments.

More recent technological developments have included implantableoccipital nerve stimulators. However, implantable nerve stimulators arecomplex, difficult to implement, and require surgical installation.Moreover, some existing topical stimulation systems do not providesufficient control of the electrical current delivery, as stimulationcurrent or voltage can vary depending on the pressure of the electrodeapplied to the skin. As a consequence, uneven and, in some cases,harmful stimulation can be applied.

Alternative systems and methods could be beneficial for the treatment ofmigraines.

SUMMARY

Disclosed herein are devices, systems and methods for non-invasivetreatment of migraine headaches and other pain using electricalstimulation. In certain aspects, a hand-held, non-invasive system isconfigured to transmit electrical stimulation through a patient's skinto a nerve beneath the skin. In some embodiments, the system isstructured as a hand-held device, that is self-applied by the patientpressing the device by against the back of the neck in the generalvicinity of the occipital nerves or against other areas in need of painrelief.

In certain aspects, the system includes a housing with a controllerhaving a signal generator. A conductive surface in electricalcommunication with a first signal line of the signal generator iscoupled to an exterior surface of the housing, and a repositionableelectrode is disposed with respect to the housing to provide improvedcontrol of the stimulation signal, for example, to modulate the pressureof the electrode at the skin, thereby providing a more even delivery ofcurrent (or voltage) for the stimulation signal. The applied pressurebetween the electrode and the skin can affect the contact area betweenthe electrode and the skin, and in turn, the impedance of the interfaceand resulting stimulation signal. In certain approaches, the systemdelivers an electrical stimulation signal only when sufficient orappropriate pressure is applied to the electrode at the patient's skin.In certain embodiments, a gating switch is used to couple and decouplethe electrode to a second signal line of the signal generator. Forexample, closing the gating switch electrically couples the electrodeand the second signal line, and opening the gating switch decouples theelectrode. and the second signal line. In certain approaches, the gatingswitch is open when the electrode is in a first position with respect tothe housing and the gating switch is closed when the electrode is in asecond position with respect to the housing. The gating switch mayinclude a contact pad such that the electrode is spaced away from thecontact pad when in the first position and the electrode is inelectrical communication with the contact pad when in the secondposition.

In certain implementations, the device includes a chamber configured forholding a gel, such as a conductive gel. In certain approaches, thechamber is removable from the housing. Additionally or alternatively,the chamber may be fixedly coupled to the housing. The chamber includesan electrically conductive element. In some embodiments, the electrodeis in fluid communication with the chamber. In some suchimplementations, the housing includes a socket with a lip and a collar,with the electrode positioned within the socket between the lip and thecollar. The electrode may be a rollerball electrode. In certainapproaches, the rollerball electrode is located at a first end of thehousing. A plurality of electrodes is provided in certain embodiments.

In certain embodiments, the electrode has an axis and the electrode isrepositionable along the axis. The device may include a compressionspring coupled to the electrode, such that the compression spring iscompressed when the electrode is repositioned along the axis to thesecond position. The electrode may comprise a shaft and a tip. The tipmay be a ball tip.

In certain implementations, a conductive surface is coupled to a distalportion of the housing. The conductive surface may comprise a pluralityof conductive surfaces. In certain approaches, the conductive surfaceincludes an inner portion and an outer portion. The inner portion andouter portion are electrically and physically coupled, and the outerportion is formed from an electrically conductive gel. The inner portionmay be formed from an electrically conductive metal.

In another aspect, systems are configured to transmit electricalstimulation through a patient's skin to a nerve beneath the skin, whichincludes a housing with a controller having a signal generator, and aconductive surface in electrical communication with a first signal lineof the signal generator, which is coupled to an exterior surface of thehousing. An electrode in electrical communication with a second signalline of the signal generator extends from the housing. In certainembodiments, the system is configured as a hand-held device, and thepatient can self-apply the device to apply electrical stimulation to theneck, occipital nerve, or other areas in need of pain relief.

In certain implementations, the conductive surface is metal. A pluralityof conductive surfaces is provided in some embodiments. In certainimplementations, the conductive surface is part of the stimulationcircuit, functioning as part of the return electrical path whencontacted by human skin. Thus, when the user grasps the one or moreconductive surfaces, the circuit is completed, thereby triggeringgeneration of stimulation current by the signal generator.

In certain embodiments, the electrode comprises a shaft and a tip. Thetip may be configured to be rounded or a ball tip. The shaft may beconfigured to be substantially rigid. A plurality of electrodes isprovided in certain embodiments. The electrodes extend from the housingand are in electrical communication with the signal generator via asignal line. In certain implementations, the inter-electrode spacing isbetween approximately 1 millimeter (mm) and approximately 10 mm. Incertain implementations, a gel is used with the electrode to provide astable, conductive interface between the electrode and the skin. The gelmay be coupled directly to the tip of the electrode. In certainimplementations, the gel is composed of a silicone or a hydrogel. Incertain approaches, the gel includes a therapeutic agent.

In certain implementations, the electrode is coupled to a gating switchwhich opens and closes the electrical communication between theelectrode and the signal generator. Closing the gating switchelectrically couples the electrode and to the signal generator, andopening the gating switch decouples the electrode and the signalgenerator. The electrode may be repositionable along a central axis suchthat when in a first position, the switch is open and when in a secondposition, the switch is closed.

The device includes a controller for delivering electrical stimulationtherapy. The controller includes a signal generator. In certainembodiments, the controller includes a programmable processor. A powersource, such as a battery, is also provided. A finger-activated switchis provided, being disposed along the housing to adjust the parametersof the electrical stimulation, such as amplitude and frequency, or toturn the device on and off. In certain implementations, the device isconfigured to be turned off While delivering electrical stimulation.

In certain implementation, a housing of the device includes a chamberfor retaining a conductive gel. In certain approaches, the chamber isremovable from the housing. Additionally or alternatively, the chambermay be fixedly coupled to the housing. The chamber includes anelectrically conductive element. The chamber may include an apertureconfigured to allow air to enter the chamber when gel is removed fromthe chamber. In certain approaches, the aperture includes a scrim. Thescrim may be permeable to air, but impermeable to gel. In someembodiments, the electrode is in fluid communication with the chamber.In some such implementations, the housing includes a socket with a lipand a collar, with the electrode positioned within the socket betweenthe lip and the collar. The electrode may be a rollerball.

In another aspect, systems and methods are provided for non-invasivetreatment of migraine headaches and other pain using electricalstimulation with a repositionable electrode. In general, the technologyincludes a housing with a controller having a signal generator. Aconductive surface in electrical communication with a first signal lineof the signal generator is coupled to an exterior surface of thehousing. A contact pad is provided within the housing, wherein thecontact pad is in electrical communication with a second signal line ofthe signal generator. The electrode is configured to translate withinthe housing. When the electrode is in a first position, it is spacedaway from the contact pad. When the electrode is in a second position,it is in electrical communication with the contact pad, and thereby incommunication with the signal generator for delivery of electricalstimulation therapy. For example, the electrode may be repositionablealong a central axis of the electrode. In use, the electrode istranslated to the second position by contacting the skin of the patientand applying sufficient pressure, at which point electrical stimulationtherapy is delivered. In certain embodiments, a plurality of contactpads are provided.

The device may include additional structures and features for effectivedelivery of electrical stimulation therapy. For example, the electrodesmay also include a rigid shaft and a ball tip, and, in certainimplementations, have a conductive gel surface at the tip. In certainembodiments, a compression spring is provided that is coupled to theelectrode to regulate the pressure needed to reposition the electrode tothe second position. In certain embodiments, a plurality ofrepositionable electrodes are provided. The plurality of electrodes maybe concentric electrodes.

In another aspect, systems are configured to transmit electricalstimulation through a patient's skin to a nerve beneath the skin, whichincludes a housing with a controller having a signal generator, a firstcontact pad in electrical communication with a first signal line of thesignal generator, a first electrode extending from the housing and inelectrical communication with the first contact pad, a second contactpad in electrical communication with a second signal line of the signalgenerator, and a second electrode extending from the housing and inelectrical communication with the second contact pad.

In certain implementations, the first electrode is axiallyrepositionable such that the first electrode is spaced away from thefirst contact pad when in a first position and is in electricalcommunication with the first contact pad when in a second position. Thesystem may include a first compression spring coupled to the firstelectrode, such that the first spring is compressed when the firstelectrode is in the second position. For example, the first electrodemay actuate the first contact pad when the first electrode isrepositioned to the second position. In certain approaches, the secondelectrode is axially repositionable such that the second electrode isspaced away from the second contact pad when in a third position and isin electrical communication with the second contact pad when in a fourthposition. In certain embodiments, the system includes a secondcompression spring coupled to the second electrode such that the secondspring is compressed when the second electrode is in the fourthposition. For example, the second electrode may actuate the secondcontact pad when the second electrode is repositioned to the fourthposition.

In certain embodiments, the first electrode has a shaft and the secondelectrode has a shaft, and the shaft of the first electrode and shaft ofthe second electrode are substantially parallel. For example, the firstelectrode and second electrode may have an inter-electrode spacing ofbetween approximately 1 mm and approximately 10 mm. In certainapproaches, the first electrode at least partially surrounds the secondelectrode. For example, the first electrode and second electrode may beconcentric. In certain embodiments, the first electrode has a tip andthe second electrode has a tip, and a first conductive gel is coupled tothe tip of the first electrode and a second conductive gel is coupled tothe tip of the second electrode. In certain approaches, the firstconductive gel and the second conductive gel are physically andelectrically coupled. In certain embodiments, the first electrode isremovably coupled to housing. In certain embodiments, the secondelectrode is removably coupled to housing.

In certain approaches, the controller includes a programmable processor.A power source, such as a battery, is also provided. In certainimplementation, a housing of the device includes a chamber for retaininga conductive gel. In certain approaches, the chamber is removable fromthe housing. Additionally or alternatively, the chamber may be fixedlycoupled to the housing. The chamber includes an electrically conductiveelement. The chamber may include an aperture configured to allow air toenter the chamber when gel is removed from the chamber. In certainapproaches, the aperture includes a scrim. The scrim may be permeable toair, but impermeable to gel. In some embodiments, the electrode is influid communication with the chamber. In some such implementations, thehousing includes a socket with a lip and a collar, with the electrodepositioned within the socket between the lip and the collar. Theelectrode may be a rollerball.

In certain aspects, methods of non-invasively treating patient pain aredisclosed herein. For example, methods are included that involvepositioning a first electrode on skin at a location near a patient'soccipital nerve or other parts of the patient, electrically coupling thefirst electrode to a second electrode, applying pressure to the firstelectrode to translate the electrode along an axis to be in electricalcommunication with a signal generator, and delivering current throughthe first electrode. The first electrode translates along an axis byapplying pressure to the skin with the electrode, and thereby closes aswitch to form a complete electrical circuit. In certain embodiments,the second electrode is placed on the skin of the patient and functionsas a return electrode. The second electrode may also be held by thepatient. Methods are further provided to adjust the current levels.

In another aspect, systems and methods are provided for transmittingelectrical stimulation to a nerve with a device that can be coupled tothe therapy site, such as a patient's head or neck. In general, thetechnology includes a controller having a signal generator, a electrodesupport having a first electrode and second electrode coupled to thesignal generator by a first signal line, and a patch having a thirdelectrode and fourth electrode coupled to the signal generator by asecond signal line. In general, the first electrode is electricallycoupled to the fourth electrode and the second electrode is electricallycoupled to the third electrode. The first electrode and second electrodeare electrically independent. The third electrode and fourth electrodeare electrically independent. In certain approaches, the first signalline and second signal line may each comprise a plurality of signallines.

Methods of non-invasively treating patient migraines with a plurality ofelectrical signals are also disclosed herein. For example, methods areincluded that involve positioning a first electrode, a second electrode,a third electrode, and a fourth electrode on a patient's skin at alocation near the patient's occipital nerve such that the electrodes arespaced away from each other. The first and fourth electrodes form aconductive path through which a first electrical signal is delivered.Additionally, the second and third electrodes form a conductive paththrough which a second electrical signal is delivered simultaneouslywith the first electrical signal. The first and second electrodes may becoupled to a electrode support on the patient's head. The second andthird electrodes may be coupled to a patch positioned on the patient'sskin. In certain approaches, the first conductive path and secondconductive path intersect. The interference of the first electricalsignal and second electrical signal forms a beat wave. In certainimplementations the first electrical signal has a frequency differentfrom a frequency of the second electrical signal by betweenapproximately 1 Hz and 100 Hz. In certain approaches, the firstelectrical signal has a frequency between approximately 3500 Hz and 4500Hz.

Methods are also provided for identifying a therapy site. In certainapproaches, methods are included that involve placing a first electrodeand a second electrode in a first configuration on a patient's skin,such that the first electrode and second electrode are electricallycoupled through the patient's tissue and form a conductive path that isapproximately longitudinally along the patient's nerve. These methodsalso include delivering a first electrical signal while the firstelectrode and second electrode are in the first position, andidentifying an effect of the first electrical signal. The method mayfurther include placing the first electrode and second electrode in asecond position, such that the first electrode and second electrode areplaced on different sides of a longitudinal axis of the patient's nerve,delivering a second electrical signal while the first electrode andsecond electrode are in the second position, and identifying an effectof the second electrical signal. In certain embodiments, the first andsecond electrodes are spaced between approximately 1 mm andapproximately 10 mm apart in the first position. The method may involveidentifying a therapy site after delivering the first electrical signaland second electrical signal, and then marking the therapy site.

In certain aspects, a hand-held, non-invasive device is configured totransmit electrical stimulation through a patient's skin to a nervebeneath the skin, which includes a housing having an exterior surface, acontroller having a signal generator disposed within the housing, aconductive surface coupled to the exterior surface of the housing, and arepositionable electrode disposed with respect to the housing. Thesignal generator has a first signal line and a second signal line. Theconductive surface is in electrical communication with the first signalline of the signal generator. The electrode is electricallydiscontinuous from the second signal line when in a first position andwherein the electrode is in electrical communication with the secondsignal line when in a second position. The device may include a contactpad within the housing and in electrical communication with the secondsignal line of the signal generator such that the electrode is spacedaway from the contact pad when in the first position and the electrodeis in electrical communication with the contact pad when in the secondposition.

The electrode may have an axis and be reposition able along the axis.The device may include a compression spring coupled to the electrode,such that the spring is compressed when the electrode is repositionedalong the axis to the second position. For example, the electrodeactuates the contact pad when the electrode is repositioned to thesecond position. In certain approaches, the electrode comprises a shaftand a tip. The tip may be a ball tip. In certain embodiments, theelectrode comprises a plurality of electrodes disposed at a first end ofthe housing.

In certain aspects, a hand-held, non-invasive device is configured totransmit electrical stimulation through a patient's skin to a nervebeneath the skin, which includes a housing, a chamber within the housingconfigured for holding a gel, a controller having a signal generatordisposed within the housing, a return electrode, and a repositionablerollerball electrode disposed with respect to the housing and in fluidcommunication with the chamber. The signal generator has a first signalline and a second signal line. The return electrode is in electricalcommunication with the first signal line of the signal generator. Theelectrode is electrically discontinuous from the controller when in afirst position and the electrode is in electrical communication with thesecond signal line when in a second position.

In certain approaches, the chamber is removable from the housing.Additionally or alternatively, the chamber may be fixedly coupled to thehousing. The chamber includes an electrically conductive element. Thechamber may include an aperture configured to allow air to enter thechamber when gel is removed from the chamber. In certain approaches, theaperture includes a scrim. The scrim may be permeable to air, butimpermeable to gel. In some embodiments, the electrode is in fluidcommunication with the chamber. In some such implementations, thehousing includes a socket with a lip and a collar, with the electrodepositioned within the socket between the lip and the collar.

In certain aspects, a hand-held, non-invasive device is configured totransmit electrical stimulation through a patient's skin to a nervebeneath the skin, which includes a housing having an exterior surface, achamber within the housing configured for holding a gel, a controllerhaving a signal generator disposed within the housing, a conductivesurface coupled to the exterior surface of the housing, and a rollerballelectrode disposed with respect to the housing and in fluidcommunication with the chamber. The signal generator has a first signalline and a second signal line. The conductive surface is in electricalcommunication with the first signal line of the signal generator. Thehousing is substantially cylindrical. In certain embodiments, theconductive surface is coupled to a distal portion of the housing. Theconductive surface may comprise a plurality of conductive surfaces. Theconductive surface includes an inner portion and an outer portion, suchthat the inner portion and outer portion are electrically and physicallycoupled. The outer portion is formed from a conductive gel. The innerportion is formed from a conductive metal. The device may include agating switch coupled to the electrode and the second signal line, suchthat closing the gating switch electrically couples the electrode andthe second signal line, and opening the gating switch decouples theelectrode and the second signal line.

Variations and modifications of these embodiments will occur to those ofskill in the art after reviewing this disclosure. The foregoing featuresand aspects may be implemented, in any combination and subcombinations(including multiple dependent combinations and subcombinations), withone or more other features described herein. The various featuresdescribed or illustrated above, including any components thereof, may becombined or integrated in other systems. Moreover, certain features maybe omitted or not implemented.

Further features, aspects, and advantages of various embodiments aredescribed in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate certain implementations and, together withthe description, serve to explain various examples of the devices,systems and methods disclosed herein.

FIGS. 1A-1B illustrate paths along a patients head indicating theapproximate location of certain occipital nerves.

FIG. 2 is a perspective view of an illustrative hand-held, non-invasiveelectrical stimulation device for the treatment of pain.

FIG. 3 is an exploded view of certain components of the device of FIG.2.

FIG. 4 is a block diagram of an illustrative therapeutic current pathassociated with an electrical stimulation device, such as the device ofFIG. 2.

FIG. 5A is a perspective view of an illustrative embodiment of theapplication of the electrical stimulation device of FIG. 2 to the backof a patients head for the stimulation of the occipital nerve for reliefof migraine headaches.

FIG. 5B is a block diagram of the therapeutic current path according tothe illustrative embodiment of FIG. 5A.

FIG. 6 is a perspective view of an electrical stimulation systemincluding the device of FIG. 2.

FIG. 7A is a perspective view of the system of FIG. 6 as applied to theback of a patient's head for the stimulation of the occipital nerve forrelief of migraine headaches, according to one implementation.

FIG. 7B is a block diagram of an illustrative therapeutic current pathassociated with an electrical stimulation system, such as the system ofFIG. 7A.

FIG. 8 is a flow diagram of the signal processing performed by acontroller included in a hand-held electrical stimulation device.

FIGS. 9A-9B are side views of an electrical stimulation device with adepressible electrode.

FIG. 10 is a block diagram of an illustrative therapeutic current pathassociated with an electrical stimulation device, such as the device ofFIGS. 9A-9B.

FIGS. 11A-11B, 12A-12B, 13A-13B, 14A-14B, 15A-15B are cross-sectionalviews of illustrative switching mechanisms for an electrical stimulationdevice with a depressible electrode.

FIG. 16A is a perspective view of an illustrative housing connector witha plurality of electrodes that may be used with an electricalstimulation device.

FIGS. 16B-16C are block diagrams of illustrative current paths between asignal generator and the plurality of electrodes of the housingconnector of FIG. 16A.

FIG. 17A is a side view of an illustrative housing connector with anadapter for receiving an electrode or other stimulation deliverycomponent.

FIG. 17B is a perspective view of an illustrative housing connector withan adapter for receiving an electrode or other stimulation deliverycomponent.

FIGS. 18A-18B are cross-sectional views of illustrative housingconnectors with releasable electrodes.

FIGS. 19A and 19B are cross-sectional and bottom views, respectively, ofan illustrative concentric electrode system.

FIGS. 20A-20B are cross-sectional views of an illustrative concentricelectrode system in use with a depressible inner element in anon-invasive electrical stimulation device.

FIG. 21A is a side view of a plurality of electrodes at a therapy site.

FIG. 21B illustrates the current paths of the configuration of FIG. 21Aduring the delivery of electrical stimulation therapy.

FIG. 21C is a side view of the configuration of FIG. 21A with aconductive gel.

FIGS. 22A-22B are side views of an electrode with an integral conductivegel surface.

FIG. 22C is a side view of a plurality of electrodes with integralconductive gel surfaces, depicting the current paths proximal to thetherapy site.

FIGS. 23A-23B are diagrams of electrodes positioned relative to a nerve.

FIGS. 24A-24B are perspective views of an illustrative non-invasiveelectrical stimulation system.

FIG. 25 is a perspective view of a non-invasive electrical stimulationdevice coupled to a patient's head.

FIGS. 26A-26B are diagrams of example electrical stimulation waveforms.

FIG. 27 is a block diagram of electronic components of an electricalstimulation device.

FIG. 28 is a block diagram of an exemplary system for communicating withan electrical stimulation device across a communication network.

FIG. 29 is a cross-sectional view of a non-invasive electricalstimulation device with an integrated system for delivery of aconductive gel.

FIG. 30 is a perspective view of a non-invasive electrical stimulationdevice with an integrated system for delivery of a conductive gel asapplied to a patient.

FIG. 31 is a cross-sectional exploded view of a non-invasive electricalstimulation device.

DETAILED DESCRIPTION

Disclosed herein are devices, systems and methods for non-invasivetreatment of migraine headaches and other pain using electricalstimulation. In general, the technology includes a non-invasive deviceconfigured to transmit electrical stimulation through a patient's skinto a nerve beneath the skin. The device includes a housing with acontroller having a signal generator. Examples of devices that may beused to implement the controller include, but are not limited to,microprocessors, microcontrollers, integrated circuits (ICs), centralprocessing units (CPUs), programmable logic devices, field programmablegate arrays, and digital signal processing (DSP) devices. A conductivesurface in electrical communication with a first signal line of thesignal generator is coupled to an exterior surface of the housing. Anelectrode in electrical communication with a second signal line of thesignal generator extends from the housing. The patient can self-applythis hand-held device by pressing it against the back of the neck in thegeneral vicinity of the occipital nerves or by applying it to otherareas in need of pain relief.

FIG. 2 is a perspective view of a hand-held nerve stimulation device 100that may be used to provide electrical stimulation to the surface of apatient, such as the back of the patient's head for stimulating theoccipital nerves. The device 100 of FIG. 2 includes a housing 104 in theform of a rigid shaft that houses inner electronics, such as a powersupply and signal generator (not shown). The housing 104 is shaped likea pen. Alternative implementations include other shapes and designs ofthe housing 104 that are rigid enough to allow adequate pressure to beapplied to the back of the patient's head or to allow the device 100 tobe placed proximal to the therapy site with sufficient accuracy.

The housing 104 includes a distal portion 104 a and a proximal portion104 b, The housing 104 may be substantially cylindrical. For example,the housing 104 may be shaped similar to a pen so that it can be heldeasily in the hand of a user. The distal portion 104 a is formed of arigid material, preferably plastic, and receives the buttons 108 a and108 b. An operator uses his or her finger to actuate and control thebuttons 108 a and 108 b to turn the device on and off, increase anddecrease the levels of stimulation, and adjust other therapy settings(e.g., waveform shape, frequency). In certain embodiments, one or bothof the buttons 108 a and 108 b include potentiometers. When thepotentiometer is adjusted, the intensity of the electrical stimulationsignal provided by the device 100 is increased or decreased accordingly.

The device 100 also includes a connector 102 which connects to thedistal end 120 of the housing 104 by screw threads (not shown). Inalternative implementations, the connector 102 may be connected to thedistal end of the housing 104 by a clip, a snap fitting, glue, oranother connection mechanism, or may be integral with the housing 104.The connector 102 includes an electrode 130 for delivering electricalstimulation to a patient. The electrode 130 includes a shaft 133 thatextends from the housing 104 and a tip 131 that contacts the patient. Incertain implementations, the tip 131 has a rounded or ball-like surface.In preferred implementations, the tip 131 is non-tissue penetrating. Incertain approaches, the tip 131 has a diameter between approximately 0.5and approximately 5 mm, but may have any appropriate size for effectiveelectrical stimulation. The electrode 130 is in electrical communicationwith a signal line of a signal generator located within the housing 104,as described below. In certain implementations, the device 100 alsoincludes a clip 106 that fastens the device 100 to a secure place, suchas the operator's pocket, a notebook, or a case.

The device 100 includes one or more conductive surfaces 160 disposedalong the outer surface 105 of the housing 104. The conductive surfaces160 function as return electrodes for the current delivered by thedevice 100. The conductive surfaces 160 provide simplicity andconvenience in use because the user can simply hold the device 100 touse it, and need not place a separate return electrode on the body. Theconductive surfaces 160 may be made of a metal or a conductive polymer.In preferred implementations, the conductive surfaces 160 are made ofchrome or silver-plated aluminum, but the conductive surfaces 160 may bemade of any suitable conductive material. The conductive surfaces 160may be disposed along any part of the housing 104, including the distalportion 104 a and the proximal portion 104 b. In certainimplementations, the conductive surfaces 160 cover the entire externalsurface of the housing 104. When self-applied by a patient, the patientgrasps the device 100, thereby placing the tissue of the patient's handin contact with the conductive surfaces 160. When the patient thenpositions the device 100 such that the electrode 130 is in contact witha target area of the patient's tissue, current flows from a signalgenerator in the device 100, through the electrode 130, out of the tip131, through the target area on the patient, through the patient's arm,and through the conductive surfaces 160, thereby returning to the device100. This and other current flow paths are discussed in additionaldetail below. In certain implementations, the conductive surfaces 160include an outer, conductive, gel layer (not shown) for ease and comfortin gripping the device 100 and improving conductivity between anoperator's hand and the device 100. For example, the gel layer may be afirm gel which is able to retain its shape.

FIG. 3 is an exploded view of certain components of the device 100 ofFIG. 2. The proximal portion 104 b of the housing 104 forms a cap thatcontains a mounting plate 110. The mounting plate 110 mounts theinternal signal pulse generator, power supply, and other electroniccomponents (such as processing circuitry for controlling the waveformsand other operation of the device, not shown) and seats the buttons 108a and 108 b (or their interface to the controller or signal generator).In some implementations, the mounting plate 110 is a printed circuitboard (PCB). In certain implementations, wires 112 are used to connectthe electronics on the mounting plate 110 to the buttons 108 a and 108 band to the connector 102. In alternative implementations, the electroniccomponents are connected directly to the mounting plate 110 or to eachother.

FIG. 4 is a block diagram of an illustrative therapeutic current pathassociated with an electrical stimulation device, such as the device ofFIG. 2, for delivering electrical stimulation therapy to a patienttherapy site to alleviate pain caused by migraines. The current path 600of FIG. 4 includes an electrical stimulation device 601 (which may besimilar to the device 100 of FIG. 2) that includes a controller 602 witha first signal line 604 that connects the controller 602 to a deliveryelectrode 606. The electrical stimulation device 601 also includes areturn electrode 614 and a second signal line 618 that connects thereturn electrode 614 to the controller 602. The controller 602 mayinclude a power source, a processing device, a signal generator, andother electronic components for delivering electrical stimulationtherapy to the therapy site 610 via the delivery electrode 606. Thedelivery electrode 606 may include a conductive surface extending fromthe electrical stimulation device 601, such as electrode 130 of FIG. 2.

During use, the controller 602 generates current that flows from thecontroller 602 through the first signal line 604 to the deliveryelectrode 606. The current then flows from the delivery electrode 606through a conductive path 608 to the therapy site 610. The conductivepath 608 may include tissue, such as skin, and other conductivematerials, such as conductive gels. The therapy site 610 may be nervetissue, such as the occipital nerve or other nerve or muscle tissue. Thecurrent flows through the therapy site 610 and returns through aconductive path 612 (which may also include tissue such as skin) to thereturn electrode 614. The current then flows from the return electrode614 through the signal line 618 to the controller 602, forming acomplete closed circuit.

FIG. 5A is a perspective view of the electrical stimulation device ofFIG. 2 as applied to the back of a patient's head 80 for the stimulationof the occipital nerve for relief of migraine headaches. In practice, aconductive gel may be placed in the hair or on the skin over theoccipital nerve location. Conductive gel typically reduces skinirritation and provides improved electrical coupling by increasing theconductivity of the electrode-skin interface and filling contact voidsbetween the electrode and skin to provide more uniform electricalcontact. In certain approaches, a conductive gel is a jelly-likematerial. A conductive gel may be a spreadable. For example, the gel maybe a cream or a liquid. In certain approaches, the gel is a colloid. Incertain approaches, the gel is capable of being reshaped. In certainapproaches, the gel may be a solid or able to retain a specific shape. Aconductive gel may be in the form of a patch. In use, the tip 131 of theelectrode 130 of the device 100 is pressed against the skin 84 over atherapy site 87, and the amplitude of the stimulation is increased to acomfortable level that may be maintained until a treatment regimen iscomplete. In certain approaches, the device 100 delivers conductive gelto the skin 84 when pressed against the skin 84, as described in furtherdetail below in relation to FIG. 29 and FIG. 30. The therapy site 87 mayoverlie nerve tissue such as the occipital nerve (e.g., occipital nerve90), or other nerve or muscle tissue.

The device 100 is actuated and adjusted to provide appropriatestimulation levels by increasing and decreasing the current via thebuttons 108 a and 108 b, for example. In certain cases, the stimulationparameters (e.g., waveform shape, amplitude, and frequency) areprescribed by a physician or other caregiver. In certain cases, thestimulation is applied for a predetermined period of time. In certaincases, the treatment regimen is applied for a predetermined time, butcontinued until the patient experiences a reduction in pain. Thestimulation current actually felt by the patient will vary according toseveral factors, including the amplitude of current delivered and theelectrical impedance of the skin, muscle, and other tissue between theelectrodes 130 and the target delivery site.

In some implementations, the device 100 generates and delivers a currentonly when sufficient pressure is applied to the electrode 130 at theskin 84. For example, the electrode 130 may be coupled to apressure-sensitive gating switch, which electrically couples theelectrode 130 to the signal generator of the device 100 when sufficientpressure is applied, and decouples the electrode 130 and the signalgenerator otherwise.

In preferred implementations, the tip 131 is a rounded, ball-likesurface that may be comfortably pressed against the skin of the patient.A ball-like tip 131 also increases the surface area of the contactinterface between the skin 84 and the electrode 130 for more controlledcurrent flow to the therapy site 87. In particular, the caregiver or thepatient can apply the device 100 at varying levels of pressure to varythe contact area between the tip 131 and the skin 84, which may changethe impedance between the electrode 130 and the therapy site 87 andthereby change the amount of current delivered to the therapy site 87.For example, in a constant voltage implementation, the device 100 ispressed against the patient's skin at a first level of pressure, suchthat a portion of the surface area of the tip 131 contacts the skin 84.The pressure is subsequently increased to press the tip 131 into theskin 84, indenting it somewhat and thereby increasing the surface areaof the skin 84 that contacts the electrode 130. This increased contactarea between the tip 131 and the patient reduces the electricalimpedance between the electrode 100 and the therapy site 87, andinversely and proportionally increases the stimulation current providedto the patient without otherwise adjusting parameters of the stimulation(e.g., using the buttons 108 a and 108 b). In constant current modes ofuse, this adjustment changes the power consumed by the device 100.

Moreover, increasing the pressure of the contact between the tip 131 andthe skin 84 compresses the tissue below the skin 84, thereby moving thetip 131 closer to the therapy site (e.g., a target nerve or otherregion) and reducing the electrical impedance of intervening muscle andother tissue. This may provide more energy to the therapy site andpotentially more relief to the patient. For example, pressing the tip131 into the skin 84 can improve stimulation delivered directly to theoccipital nerve 90, which is located between approximately 3 mm and 17mm below the skin 84. In this way, the operator can not only adjust theamount of energy generated by the device, but can adjust the amount ofthat energy that actually reaches the therapy site, and therefore canmore precisely adjust the treatment applied.

A small tip 131 of the device 100 allows a larger current density at theskin contact site as compared to standard electrodes. The larger currentdensity can permit a more precise stimulation delivery by allowing thecurrent to reach the fine motor points more easily. In particular, alarge current density more easily overcomes the resistance by muscle andother tissue between the tip 131 of the device 100 and the therapy site.The current that reaches the therapy site would therefore be distributedover a smaller area and potentially more beneficial to the patient.

When a gel is used at the skin surface, the current density of thestimulation therapy is also a function of the diameter, thickness, andconductivity of the gel through which the stimulation is directed. Incertain implementations, the type of gel used and the geometry of itsapplication are adjusted to more effectively provide stimulationtherapy, as described below. For example, the electrode may be providedwith an integral conductive gel coating, or the conductivity of the gelmay be tuned to selectively direct current through one or more paths.

In certain implementations, the tip 131 of the electrode 130 providesfor sufficient current density so that electrical stimulation can beapplied in therapeutic settings where the patient is using medicatedcream or other ointments that make it difficult to use standardelectrical stimulation devices. For example, BENGAY® and other medicatedpastes are not typically used with standard wide-area electrodes (suchas standard TENS electrodes) for treating orthopedic pain, because thehydrogels commonly used with such electrodes (such as those containing aglycerin base with electrolytes) do not adhere well to such pastes. Asmall tip 131 alleviates the need to use a glycerin or other hydrogel toachieve sufficient current delivery, which can allow the device 100 tobe applied with medicated creams and pastes.

The device 100 can therefore be used to deliver electrical stimulationtherapy in place of devices that use large electrodes with hydrogelinterfaces. The device 100 can also be used to treat other anatomicalareas besides the occipital nerve, including the back of a patient'sknee or other anatomical areas. In alternative implementations, the tip131 of the electrode 130 may include a needle or other sharp tip thatcan penetrate the tissue of the patient to provide improved acupuncturetherapy or related therapies. In certain implementations, the electrode130 is removable from the device 100, and may be interchanged with otherelectrode structures including, but not limited to, needle electrodesand pad electrodes.

The device 100 may also include a marking element, such as a pen ormarker tip. A marking element may be useful to mark a therapy site, suchas the therapy site 87. In use, a physician, therapist, or other careprovider, may use the device 100 to stimulate nerve or muscle tissue andelicit a response. For example, the patient may experience reduced painor, in the case of stimulating muscle tissue or the nerve connected tomuscle tissue, the stimulation current may cause a muscle twitch. Incertain embodiments, the device 100 may be used by a surgeon (e.g., ahand or foot surgeon) to identify and mark a motor point. For example,the motor point may be the target of a surgical procedure or may beidentified as a therapy site for nerve or muscle electrical stimulationtreatment. The care provider can then use the marking element to circlea therapy site, trace a nerve, or otherwise provide instructive marksfor improved therapy. In certain approaches, the marking element isattachable to the device 100. For example, the marking element may be anattachable cartridge. The cartridge may slide over and clamp onto thedistal end 120 of the housing 104. In certain approaches, the markingelement is interchangeable with the electrode 130. For example, thedevice 100 may function similarly to a multi-tip pen, with at least onetip being an electrode (e.g., the electrode 130), and a second tip beinga marking element. The tips may be interchangeable, for example, bypushing a button or rotating the housing 104. In some implementations,the electrode 130 is removable and replaceable with a marking element.

As described above with reference to FIG. 4B, during use of theelectrical stimulation devices described herein, a closed current pathbetween the electrical stimulation device and the therapy site isformed. FIG. 5B is a block diagram of the therapeutic current path 620between a controller 622 of the device 100 and the therapy site 87,according to the illustrative embodiment of FIG. 5A. The current path620 forms a closed electrical circuit from the controller 622 throughthe delivery electrode 130, to the therapy site 87, through thepatient's hand 78, and back through the conductive surfaces 160 to thecontroller 622. In particular, the controller 622 (which may include apower supply such as a battery, a signal generator, a processing device,and other electronic components) produces a current that flows from thecontroller 622 through the first signal line 624 to the electrode 130.The signal line 624 may include a wire or other conductive surface, suchas the wire 112 depicted in FIG. 3. When the electrode 130 is pressed tothe skin 84 of the patient, a conductive path 626 is formed between theelectrode 130 and the therapy site 87. The conductive path may includethe patient's skin, as well as intervening conductive materials such asa conductive gel. The therapy site 87 may include muscle or nervetissue, such as the occipital nerve. In the embodiment of FIG. 5A, thestimulation current flows through the therapy site 87 to the patient'sarm and hand 78 through a conductive path 628 which includes thepatient's inner tissue. The patient's hand 78 touches at least one ofthe conductive surfaces 160 of the device 100 to form a conductive path630. The conductive surfaces 160 function as a return electrode for thetherapeutic current, and return that current to the controller 622 via asecond signal line 632 (e.g., the wire 112 or another conductiveelement).

The devices, systems and methods disclosed herein provide an advanceover existing technologies. For example, there is no need for aninvasive surgery or implantation of the device 100, which eliminatessurgical costs and associated risks such as infection and electricallead wire migration. The device 100 can be produced cost-effectively.The device 100 can be used as a diagnostic tool or on a trial basisbefore implantation of an implantable stimulator, if desired. Becausethe stimulation current is applied at a relatively small location (andmay be applied along the hairline), a patient's head need not be shavedand thus cosmetic hair adjustments are not needed. Moreover, treatmenttime can be reduced because the stimulation current can be applieddirectly to an appropriate therapy site. Treatments can be easilyadjusted and applied at any convenient time for the patient. The device100 can therefore be better tailored to meet certain individual needsand, in many cases, provide faster results than medication, surgery,acupuncture therapy or other currently available treatment modes.

FIG. 6 depicts the device 100 of FIG. 2 assembled into a non-invasiveelectrical stimulation system 200 for use in applying stimulation tooccipital nerves or other tissue for the treatment of migraine headachesor other pain. The system 200 includes the device 100 as well asadditional components that may be used in certain implementations toprovide effective electrical stimulation therapy to alleviate pain. Forexample, the system 200 includes an extension electrode 202 connected tothe device 100 by an electrical lead wire 114 at a electrode jack 206.The extension electrode 202 functions as a return path for currentdelivered to a therapy site by the electrode 130 and may be provided inaddition to or in place of the conductive surfaces 160. When used, theextension electrode 202 is placed away from the therapy site (forexample, at the base of the neck, shoulder, or arm). Because the contactarea between the extension electrode 202 and the patient's tissue isgreater than the area between the conductive surfaces 160 and thepatient's tissue, using the extension electrode 202 as the returnelectrode instead of or in addition to the conductive surfaces 160 maydistribute the return current over a greater contact area and therebyreduce the current density in the user's tissue. The extension electrode202 may be used if the therapy causes discomfort at the hand when theconductive surfaces 160 are used as the only return electrodes in thecurrent return path. In certain implementations, both the conductivesurfaces 160 and the extension electrode 202 are provided and used asreturn electrodes. In certain implementations, a plurality of extensionelectrodes 202 are provided and used. In certain implementations, theextension electrode 202 is releasably attached to the device 100. Theextension electrode 202 may be disposable and replaceable for improvedconvenience and sanitation.

The extension electrode 202 includes an electrically conductive surface210. The conductive surface 210 may be made of metal or conductivepolymer (e.g., chrome, silver-plated aluminum, silver chloride, or anysuitable conductive material). The extension electrode 202 includes abacking layer 208 for handling the extension electrode 202. In certainembodiments, the backing layer 208 is peeled off when applied to thepatient. For example, backing layer 208 may protect an adhesive surfacefor attaching the extension electrode 202 to the skin of a patient. Incertain implementations, the adhesive surface is a conductive coatingover the conductive surface 210. For example, the adhesive surface mayinclude silicone, other polymers such as polyvinylpyrollidone,polyethylene oxide, polyvinyl alcohol, polyethylene glycol,polyacrylamide, or polysaccharides, such as gum karaya.

The device 100 of the system 200 of FIG. 6 includes a status indicator170. The status indicator 170 informs a user of the operational statusof the device 100 and can come in the form of a visual, an audible,and/or a tactile indicators. Examples of suitable status indicatorsinclude a light, an LED, a liquid crystal or other type of display, aspeaker, a buzzer, and a vibration motor. The status indicator 170 maybe used to indicate any of a number of therapeutic or other conditions.For example, the status indicator 170 may be used to indicate whetherthe device 100 is ON or OFF. The status indicator 170 may be used toindicate whether the electrode 130 is applied to the skin withsufficient pressure to activate the device 100 for delivery of astimulation current. The status indicator 170 may be used to indicate anoperational mode, such as a type of therapy being provided, or a changein operational mode, such as an increase or decrease in stimulationcurrent amplitude. For example, the device 100 may be configured so thatthe status indicator 170 includes one or more LEDs that emit certaincolors that correspond with the amplitude of the therapy beingdelivered. The status indicator 170 may be used to show battery powerstatus (e.g., full power, percentage of full power, or low on power/inneed of charge), or charging status (e.g., charging or fully charged).Other types indicators are used in other possible embodiments. Speakers,buzzers, and vibration motors are particularly useful for those withcertain disabilities or impairments and are also useful forcommunicating information to a patient when the device 100 is being usedin an area that is not easily visible (e.g., on the patient's back). Incertain embodiments, the status indicator 170 allows an operator to viewcurrent operating parameters, view historical user data (such asperformance and use statistics), view current physiological parameters(such as muscle feedback signals, heart rate). For example, the statusindicator 170 may show a selection menu for making therapy adjustmentswith buttons 108 a and 108 b. The status indicator 170 may also providea display with instructions or progress updates when the operatordownloads additional programs or firmware to the internal controller.Although only a single status indicator is shown in FIG. 6, two or morestatus indicators may be included with the device 100 to perform any oneor more of the functions described above, or any other suitablefunction.

The device 100 includes a port 164, which can receive an input from oneor more external sources. For example, the port 164 may be configured asa recharging port which receives an electrical connector to recharge thebattery of the device 100. In certain implementations, the device 100can be powered by an external power supply connected via port 164, insome implementations, the port 164 includes a thermistor to monitor thetemperature of a battery included with the device 100 during charging toavoid overheating. In some such implementations, the charge level isindicated by the status indicator 170. In certain implementations, thephysician or technician connects the device 100 to bedside equipment viaa connection with the port 164 (which may be, for example, a USB port),to download data from the device 100 or upload data to the device 100.In certain embodiments, port 164 is used to download stimulationprotocols or update firmware for the internal controller.

FIG. 7A is a perspective view of the system 200 of FIG. 6 as applied tothe back of a patient's head 80 for the stimulation of the occipitalnerve for relief of migraine headaches, according to one implementation.A patient or caregiver places the extension electrode 202 on theshoulder or neck 88 of the patient, and applies the tip 131 of theelectrode 130 to a therapy site 87 on the back of the patient's head 80in the vicinity of the occipital nerve. In preferred implementations,the extension electrode 202 includes an adhesive surface that holds theextension electrode 202 against the patient's tissue. As shown, theextension electrode 202 is placed away from the therapy site 87. Forexample, in the depicted case, the extension electrode 202 is placed atthe base of the neck 88. The extension electrode 202 may be placed atany location which is comfortable for the patient, including, but notlimited to the shoulder, back, and arm. The device 100 is actuated andadjusted to provide appropriate stimulation levels by increasing anddecreasing the current via the buttons 108 a and 108 b, for example. Anelectrical stimulation current flows out of the electrode 130, passesthrough the therapy site 87, and returns to the device 100 via theextension electrode 202.

FIG. 7B is a block diagram of a therapeutic current path 640 for thedelivery of stimulation treatment according to the embodiment of FIG.7A. The path 640 is similar to the path 620 of FIG. 5B in that it formsa closed electrical circuit for delivering current, with the primarydifference being that the path 640 includes an extension electrode 202.As shown, current flows from the controller 622 through the electrode130, to the therapy site 87, and returns through the extension electrode202 to the device 100. Instead of flowing through the patient's hand asin current path 620 of FIG. 5B, the current flows through the conductivetissue path 642 disposed between the therapy site 87 and the extensionelectrode 202. As described above, the extension electrode 202 may beplaced at any comfortable location on the body including, but notlimited to, the neck and shoulder. The extension electrode 202 iselectrically connected to the controller 622 by the lead wire 114.

In preferred implementations, a hand-held electrical stimulation device(such as the device 100 of FIG. 2) is provided with a controller thatproduces an electrical stimulation waveform with desiredcharacteristics. FIG. 8 is a flow diagram of the signal processingperformed by a controller 622 included in such an electrical stimulationdevice. The controller 622 includes a processor 650 and signal generator660. Examples of devices that may be used to implement the processor 650include, but are not limited to, microprocessors, microcontrollers,integrated circuits (ICs), central processing units (CPUs), programmablelogic devices, field programmable gate arrays, and digital signalprocessing (DSP) devices. The processor 650 may be of any generalvariety such as reduced instruction set computing (RISC) devices,complex instruction set computing (CISC) devices, or specially designedprocessing devices such as application-specific integrated circuit(ASIC) devices. Examples of devices that may be used to implement thesignal generator 660 include, but are not limited to, those described inU.S. Pat. Nos. 4,887,603 and 4,922,908, both by Morawetz et al. andtitled MEDICAL STIMULATOR WITH STIMULATION SIGNAL CHARACTERISTICSMODULATED AS A FUNCTION OF STIMULATION SIGNAL FREQUENCY, the contents ofwhich are hereby incorporated by reference in their entireties. In someimplementations, the signal generator 660 is a simple modulated pulse(SMP) signal generator. In use, the signal generator 660 is electricallycoupled to an output (not shown), such as electrode 130 of FIG. 2, todeliver electrical stimulation therapy to the patient's tissue. Thecontroller 622 may also include or be coupled to a power source, such asa battery (not shown), and actuation switches, such as the buttons 108of FIG. 2, An example of a suitable battery is a lithium-ion batteryhaving a voltage of about 3.7 to 4.2 volts, although other battery typesand voltages are used in other implementations.

As shown in FIG. 8, the processor 650 receives waveform information (forexample, from an operator of the hand-held electrical stimulationdevice) which is used by the processor 650 to output a stimulationcontrol signal. The signal generator 660 receives the stimulationcontrol signal and generates a corresponding electrical stimulationwaveform for delivery to the patient. For example, the user may press anactuation button, such as the buttons 108 a and 108 b of FIG. 2, or mayprovide input information by programming the processor 650 through acommunications port (e.g., port 164 of FIG. 6) to select or adjust thefrequency, amplitude, pulse width, shape, or other characteristic of theelectrical stimulation waveform. In certain implementations, theprocessor 650 receives waveform information from a caregiver's computeror other source. In response to the input waveform information, theprocessor 650 outputs a stimulation control signal to the on-boardsignal generator 660. The processor 650 may be programmable (e.g., aprogrammable microprocessor) and may be configured with software loadedinto a memory on-board the hand-held electrical stimulation device. Incertain implementations, software is used to program the processor 650with information about different stimulation control signals that, whengenerated by the processor 650 and transmitted to the signal generator660, cause the signal generator 660 to generate different desiredelectrical stimulation waveforms. These waveforms may have predeterminedamplitudes and frequencies that are fixed or that vary in response toinputs to the processor 650. The controller 622 may be programmed toadjust the therapy waveforms over a specific time, for example,according to a programmed schedule. In certain embodiments, thecontroller output includes a series of different waveforms, for example,a first, low amplitude signal followed by a second, high amplitudesignal, or a first signal at a first frequency followed by a secondsignal at a second frequency. In certain embodiments the waveformparameters vary periodically. In alternative embodiments, the waveformparameters vary at random intervals. The current and voltage can also bevaried.

Other configurations and electrical signals are possible, and may beprescribed by a physician or adjusted by the patient. In certainimplementations, the controller 622 may be configured to generate one ormore electrical stimulation waveforms determined to be appropriate forthe patient according to tests performed at the patient's bedside usingbedside equipment. For example, a physician could use a bedsideelectrical stimulation system to determine the appropriate frequency andother parameters of an electrical stimulation waveform that alleviatespatient pain. A waveform with those parameters would then be configuredinto the controller 622 of the hand-held electrical stimulation device(e.g., the device 100 of FIG. 2), and the device could then be sent homewith the patient for ongoing use. In certain implementations, thewaveform parameters are transmitted to the hand-held stimulation devicewhen the physician or technician connects the device to the bedsideequipment by a docking station on the equipment or by a cable connection(e.g., via a USB connection to port 164 of FIG. 6) and actuates theprocessing circuitry of the bedside equipment via a user interface onthe equipment to download the appropriate waveform(s) onto thecontroller 622 of the device. In some implementations, data transmissionbetween the bedside equipment and the hand-held stimulation deviceoccurs wirelessly, using WiFi, Bluetooth™, another radio frequencycommunication protocol, or another suitable wireless communicationtechnique. The bedside equipment can also be configured with Internet orother network connectivity to allow data downloading onto the hand-helddevice.

In some implementations, the controller 622 controller 622 may beprogrammed to sense impedance and deliver therapy accordingly. Forexample, the controller 622 can be programmed such that if a lead (e.g.,the electrode 130 or conductive surfaces 160 of FIG. 2, the extensionelectrode 202 of FIG. 6, etc.) loses electrical contact with thepatient's tissue during therapy, the controller 622 detects the opencircuit and modifies the applied electrical stimulation appropriatelyuntil the lead makes contact. For example, the controller 622 may beprogrammed to shut down the delivery of electrical stimulation to theopen lead and to issue an alarm, such as an audible tone. In alternativeembodiments, the controller 622 detects a short between two leads. Forexample, if two leads (e.g., electrode 130 and extension electrode 202)are physically touching or spaced too closely, the controller 622 may beprogrammed to shut down the delivery of electrical stimulation betweenthe leads and to issue an alarm, such as an audible tone. In certainembodiments, the controller 622 commences delivery of a stimulationsignal based on an impedance measurement indicative of the electrode(e.g., the electrode 130) establishing sufficient contact with the skinof the patient.

In some implementations, the controller 622 is programmed to receivefeedback from the patient or operator and modify the electricalstimulation waveform applied accordingly. For example, the controller622 may be programmed to sense electromyographic biofeedback based onmuscle activity and regulate therapy accordingly. Other biofeedback suchas heart rate or activity levels may also be monitored. In someimplementations, the user provides specific feedback to the controller622. For example, the user can set therapy thresholds (magnitude,duration of therapy) that are stored in a memory accessible to thecontroller 622. The controller 622 may be programmed to adjust therapyin response to feedback, such as biological activity or impedancemeasurements.

In some implementations, the controller 622 may be configured tocommunicate with controllers of other clinical devices to coordinate thetherapy or therapies delivered to the user, thereby forming a body areanetwork. This network can be formed through wireless communicationand/or conductive communication through the patient's body. For example,the controller 622 may communicate with other stimulation or therapydevices (e.g., TENS, iontophoresis, muscle stimulation, nervestimulation, drug delivery, or monitoring devices) to providecoordinated therapy to the patient.

As discussed above with reference to the electrical stimulation device100 of FIG. 2, some of the hand-held electrical stimulation devicesdescribed herein generate and deliver current only when sufficientpressure is applied to the electrode by the patient's tissue as detectedby a pressure-sensitive switch included in the device. In certainapproaches, the electrode may be coupled to a force gauge, pressuregauge, strain gauge, load cell, piezoelectric force sensor, or otherforce sensor, pressure sensor, or switch. In some implementations, thisfunctionality is achieved with a depressible electrode. Electricalstimulation devices configured with depressible electrodes are nowdiscussed.

FIGS. 9A and 9B are side views of the electrical stimulation device 100(FIG. 2) with a depressible electrode 230. The electrode 230 may bestructurally and functionally similar to the electrode 130, but isconnected to a signal generator (e.g., the signal generator 660 of FIG.8) by a pressure switch mechanism. In preferred implementations, theelectrode 230 has a central axis 216 through the tip 231 and shaft 233of the electrode 230, and is repositionable along the central axis 216.The electrode 230 is in electrical communication with the signalgenerator of the device 100 only when sufficient pressure is applied tothe electrode 230 to cause the electrode 230 to translate along thecentral axis 216 to connect with an electrical output contact of thesignal generator and thereby form a continuous electrical communicationpath with the signal generator. The electrode 230 may thus be configuredas a conductive “push button” that is coupled to the signal generator bya single-pole, single-throw “momentary on” switch to control currentflow. For example, FIG. 9A depicts the electrode in a neutral positionaway from the skin 84 when no pressure is applied between the electrode230 and the skin 84. FIG. 9B shows the electrode 230 pressed against theskin 84 to form a depressed area 86 of the skin. When the electrode 230is pressed against the skin 84 with sufficient pressure, the electrode230 is pushed into the housing 104 of the device 100 along the centralaxis 216. When repositioned to this upper or closed position, theelectrode 230 is electrically coupled with the signal generator and candeliver current to the therapy site.

FIG. 10 is a block diagram of the therapeutic current path 680associated with an electrical stimulation device according to FIGS. 9Aand 9B. As shown, a switch 682 is disposed between the controller 642and the electrode 230. The switch 682 is a “normally open” single-pole,single-throw switch that functions as a gating switch for delivery ofelectrical stimulation therapy. The switch 682 remains open with theelectrode 230 disconnected from the controller 622 until sufficientpressure is applied to the electrode 230. When sufficient pressure isapplied to the electrode 230, the switch 682 is closed, thereby forminga continuous electrical communication path from the controller 622through the signal line 624, the switch 682, the signal line 626, andthe electrode 230. Current flows from the therapy site 87, through theconductive path 630 to the return electrode 614, and back to thecontroller 622 through the signal line 632. Return electrode 614 may besimilar to the conductive surfaces 160 of FIG. 2 or the extensionelectrode 202 of FIG. 6. Allowing the current to flow to the therapysite only when sufficient pressure is applied to the electrode 230provides more precise and consistent control of the current beingdelivered by ensuring that sufficient contact is made between theelectrode 230 and the skin 84 (FIGS. 9A and 9B).

FIGS. 11 through 15 are cross-sectional views of illustrativepressure-sensitive switching mechanisms for an electrical stimulationdevice with a depressible electrode. FIG. 11A depicts the electrode 230in a neutral position before being placed on the skin 84 of the patient.The shaft 233 of the electrode 230 extends from the connector 102 (FIG.2). The electrode 230 includes a column 226 which extends into a chamber229 of the housing 104 (FIG. 2). The electrode 230 also includes aretention surface 222 which contacts the bottom edge 220 of theconnector 102 to limit the vertical range of motion of the electrode230. A compression spring 224 is disposed along the column 226 betweenthe retention surface 222 and the upper edge 221 of the connector 102.As shown, the spring 224 is a coil spring, and may be made of springmetal, but other springs may also be used, including, but not limitedto, elastomeric springs.

The chamber 229 includes a contact pad 228 disposed on a wall 235. Thecontact pad 228 is an electrical conductor that is electrically coupledwith a signal line of a signal generator of the device 100 (e.g., thesignal generator 660 of FIG. 8). The contact pad 228 may be made of ametal (such as chrome, silver-plated aluminum, or silver chloride), aconductive polymer, or any suitable conductive material. As shown, whenthe electrode 230 is in a neutral position without contact or pressureat the tip 231 of the electrode 230, the electrode 230 does not comeinto electrical contact with the contact pad 228. Therefore, theelectrode 230 is not in electrical communication with the signalgenerator of the device 100 and no current is delivered to the patient.In use, the electrode tip 231 is pressed into the patient's skin 84.When pressure is applied, the skin is depressed, the spring 224 iscompressed, and the electrode 230 slides vertically within the connector102 and the chamber 229 of the housing 104. The spring 224 applies aresistive force to the electrode 230, which ensures that sufficientpressure and contact is maintained between the skin 84 and the electrodetip 231. As shown in FIG. 11B, when sufficient pressure is applied, theelectrode 230 is repositioned, the column 226 of the electrode 230touches the contact pad 228 to complete an electrical circuit to thesignal generator of the device 100, thus allowing current to flow fromthe signal generator to the electrode 230 and be delivered to thepatient therapy site. The spring constant of the spring 224 determineshow much force or pressure must be applied to the electrode 230 tocompress the spring 224 and move the electrode 230 to the upper positionshown in FIG. 11B and thereby activate the switch mechanism. A springwith a higher spring constant requires more force to compress. Thespring 224 can be chosen or designed to set the amount of pressurerequired to move the electrode to the “on” position to any appropriatelevel. This configuration ensures that the electrode 230 has sufficientcontact with the skin 84 to deliver effective, consistent and controlledelectrical stimulation therapy. When the pressure against the tip 231 isreleased, the spring 224 decompresses and slides the electrode 230vertically into the neutral position depicted in FIG. 11A.

The contact pad 228 of FIGS. 11A and 11B is depicted as a substantiallyflat contact pad disposed on the wall 235 of the chamber 229. However,contact pads may have other shapes and may be disposed on differentparts of the device 100. The contact pads may also change position orshape from the force applied when the electrode 230 is repositioned. Forexample, as depicted in FIGS. 12A and 12B, the contact pad 232 issubstantially arcuate and disposed within an aperture 234 of the wall235. When pressure is applied to the electrode 230, the compressionspring 224 is compressed and the column 226 slides within the chamber229. When sufficient pressure is applied, the column 226 contacts thecontact pad 232 to form an electrical communication path with the signalgenerator. The arcuate shape of the contact pad 232 ensures sufficientcontact between the contact pad 232 and the column 226 by applying aresistive force that flexes or flattens the contact pad 232 when incontact with the column 226. The contact pad 232 is made of a conductivematerial (for example, a conductive spring steel).

FIGS. 13A and 13B depict an electrical contact pad 236 disposed withinan aperture 240 of a top surface 238 of the chamber 229. As discussedwith reference to other implementations, when pressure is applied to theelectrode 230, the column 226 slides up the chamber 229 and compressesthe spring 224. When sufficient pressure is applied, the column 226contacts the contact pad 236 on the top surface 240 of the chamber 229.

Contact pads may also have a rounded surface shape. FIGS. 14A and 14Bdepict two rounded contact pads 242. In some implementations, thecontact pads 242 are bearings that allow the column 226 to slide withinthe chamber 229. In certain embodiments the contact pads 242 depresswhen the column 226 abuts the contact pads 242, as shown in FIG. 14B.

Contact pads may also be hinged. FIGS. 15A and 15B depict a hingedcontact pad 248 attached at a hinge point 250 to a wall 231 of thechamber 229. The contact pad 248 is electrically connected to the signalgenerator of the device. The column 226 slides within the chamber 229 tocontact the contact pad 248 and electrically couple the electrode withthe signal generator. As depicted, the column 226 pushes the contact pad228 into the upward position depicted in FIG. 15B.

A number of variations of the device 100 (FIG. 2) and the system 200(FIG. 6) are possible. For example, the device 100 may be configuredwith alternative structures for the connector 102 (FIG. 2). FIG. 16A isa perspective view of an illustrative housing connector 302 with aplurality of electrodes 130 a-130 c. As shown, the electrodes 130 a-130c are connected to the housing connector 302 by a plurality of shafts133 a-133 c. The electrodes 130 a-130 c and shafts 133 a-133 c arecomposed of a conductive materials, such as metals or conductivepolymers. In certain implementations, the electrodes 130 a-130 c andshafts 133 a-133 c are rigid, so that when applied to the housing 104 ofthe device 100, a rigid electrical stimulation device is provided. Theplurality of electrodes 130 a-130 c provide multiple surfaces forcontact with the patient's tissue and thus an increased total surfacearea for delivery of electrical stimulation therapy as compared toimplementations in which a single one of the electrodes 130 a-130 c isused. The plurality of electrodes 130 a-130 c may be used to reduce thecurrent that flows through any individual electrode to reduce the riskof skin irritation, while maintaining the total current level necessaryfor effective therapy. Additionally, the plurality of electrodes 130a-130 c may be used to provide therapy at multiple points (for example,on multiple branches of the occipital nerve 90 a-c as shown in FIG. 1).In certain embodiments, a different stimulation waveform is deliveredthrough each of the plurality of electrodes 130 a-130 c. _Although threeelectrodes 130 a-130 c are depicted, any number of electrodes may beused. For example, two electrodes may be used. In certainimplementations, at least one electrode of electrodes 130 a-130 c is areturn electrode. In certain implementations, the electrodes 130 a--130c are spaced approximately 1-10 mmm apart from each other. In certainimplementations, the edges of the electrodes 130 a-130 c are spacedapproximately 3.5 mm apart from each other and the centers of theelectrodes are spaced approximately 5 mm apart from each other. Theelectrodes 130 a-130 c may have any appropriate spacing as determinedfor effective electrical stimulation therapy. In certain approaches, oneor more of the electrodes 130 a-130 c is repositionabie, for example, asdescribed in relation to FIGS. 9A-15B).

FIGS. 16B and 16C are block diagrams of illustrative current pathsbetween a signal generator 660 (FIG. 8) and the plurality of electrodes130 a-130 c of the housing connector 302 of FIG. 16A. In FIG. 16B, asingle wire 152 connects the pulse generator 660 to a conductiveinterface 168, located within the housing 104 of the device 100 (FIG.2). At the conductive interface 168, the current flow splits into thethree different electrodes 130 a-130 c. In FIG. 16C, the pulse generator660 independently connects to the electrodes 130 a-130 c via respectiveindependent conducting lines 154, 156 and 158. Independent conductinglines 154, 156, and 158 allow for increased current carrying capacityfor treatment of more acute pain or higher amplitude stimulation. Incertain implementations, different stimulation parameters are appliedthrough different ones of the electrodes 130 a-130 c or subsets of theelectrodes 130 a-130 c. In certain implementations, a first electrode orsubset of the electrodes 130 a-130 c is used as a current deliveryelectrode and a second electrode or subset of the electrodes 130 a-130 cis used as a return electrode. In certain implementations, a firstsubset of the electrodes 130 a-130 c is connected to the signalgenerator 660 through a single conductive path and second subset of theelectrodes 130 a-130 c is independently connected to the signalgenerator 660.

FIGS. 17A-17B is a perspective view of an illustrative housing connector102 (FIG. 2) with an adapter 310 for receiving an electrode or otherstimulation delivery component. In particular, FIG. 17A depicts anadapter 310 that slides over the electrode 130 in the connector 102. Theadapter 310 is configured with a distal female jack 314 that receives amale snap 136 from a standard snap electrode 134. The proximal femalejack 312 of the adapter 310 snaps into connection with the electrode 130as the tip 131 extends into the proximal female jack 312. FIG. 17Bdepicts an adapter 310 connected to the tip 131 c of the electrode 130 cof the multi-electrode connector 302 of FIG. 16A. The adapter 310 canreceive other electrodes or other electrical components through thedistal jack 314.

FIGS. 18A-18B are cross-sectional views of illustrative housingconnectors with releasable electrodes (i.e., electrodes that areprovided separately from and attach to a connector). The housingconnector 102 of FIG. 18A has an electrode 330 with a proximal end 324that seats within a jack 121 of the connector 102, thereby putting theelectrode 330 into electrical communication with the wiring and othercomponents of the electrical stimulation device 100 (FIG. 1). In certainimplementations, the electrode 330 is releasably connected to theconnector 102. For example, the electrode 330 may be removed andreplaced for sanitation purposes. The electrode 330 may also bereplaceable so that the device 100 may be used with electrodes ofdifferent sizes or shapes to provide specific types of therapy or toaccommodate user preferences. In certain implementations, a plurality ofelectrodes 330 a-330 c attach to a connector 302, as shown in FIG. 18B.Each proximal end 324 a-324 c of the respective electrodes 330 a-330 cfits within a jack 320 of the connector 302. The electrodes 330 a-330 cmay be connected through a single conductive path to the signalgenerator, as depicted in FIG. 16B, or independently connected to thesignal generator, as depicted in FIG. 16C. In certain implementations, afirst subset of the electrodes 330 a-330 c are connected to the signalgenerator through a single conductive path and a second subset of theelectrodes 330 a-330 c are independently connected to the signalgenerator.

FIGS. 19A and 19B are cross-sectional and bottom views, respectively, ofan illustrative concentric electrode system 350 for use with anelectrical stimulation therapy system. Concentric electrodes may be usedto provide a more compact arrangement of multiple electrodes. Theelectrode system 350 has a substantially hollow outer electrode 352 withan aperture 356 at the distal end 355. The inner electrode 354 isdisposed within the hollow portion 353 of the outer electrode 352. Thehollow portion 353 may have a diameter between approximately 1 mm andapproximately 25 mm. The distal end 355 of the electrode system 350 isplaced on the patient's skin so that both the outer electrode 352 andthe inner electrode 354 are in contact with the patient's tissue. FIG.19B depicts a bottom view of the electrode 350 with the inner electrode354 disposed within the outer hollow electrode 352. In certainimplementations, the inner electrode 354 is used as a delivery electrodeto deliver a stimulation current and the outer electrode 352 is used asa return electrode. In alternative implementations, the outer electrode352 is the delivery electrode and the inner electrode 354 is the returnelectrode. In certain approaches, the inner electrode 354, the outerelectrode 352, or both the inner electrode 354 and the outer electrode352 are repositionable, for example, as described in relation to FIGS.9A-15B. Current may flow through the inner electrode 354 and the outerelectrode 352 only when sufficient pressure is applied such that therepositionable electrode (e.g., the inner electrode 354, the outerelectrode 352, or both the inner electrode 354 and the outer electrode352) is repositioned to be in electrical communication with a signalgenerator.

FIGS. 20A and 20B are cross-sectional views of a concentric electrodesystem 370 with a depressible inner electrode 374 disposed within anouter electrode 372. The shaft 378 of the inner electrode 374 extendsthrough an opening 376 of the outer electrode 372. The inner electrode374 functions similarly to the depressible electrode 230 described inFIGS. 9A and 9B. Before pressure is applied to the electrode system 370,the tip 380 of the inner electrode 374 extends beyond the opening 376 ofthe outer electrode 372 and is in a neutral state, disconnected from asignal generator (e.g., the signal generator 660 of FIG. 8). The innerelectrode 374 is depressible to control the delivery of current to thepatient. As shown in FIG. 20B, when the electrode system 370 is pressedagainst the skin 84 with sufficient pressure, the skin is depressed atregion 86 and the inner electrode 374 is repositioned within the outerelectrode 372. When repositioned, the inner electrode 374 electricallyconnects to the signal generator, and is thereby able to deliverelectrical stimulation therapy to the patient. For example, the innerelectrode 374 may be switchably connected to the signal generatorthrough any of the mechanisms depicted in FIGS. 11 through 15. Incertain embodiments, both the inner electrode 374 and the outerelectrode 372 are depressible.

FIG. 21A is a side view of a first electrode 402 and a second electrode406 disposed on the surface of the skin 84 and configured to deliverelectrical stimulation therapy to a therapy site 87. FIG. 21B depictsthe current paths of FIG. 21A during the delivery of electricalstimulation therapy. As shown, the current “i” flows through the firstelectrode 402 (“delivery electrode” or “active electrode”) and returnsthrough the second electrode 406 (“return electrode”). The path of thecurrent between the first electrode 402 and the second electrode 406 isdetermined primarily by the impedance between the electrodes 402 and 406along various paths. The various current paths are effectively currentdividers for the therapy current. For example, as shown in FIG. 21B,current “i₁” and current “i₂” are fractional components of the totalcurrent “i” delivered by the electrodes 402 and 406. The magnitude ofcurrent “i₁” and current “i₂” are determined by the impedance of thecurrent pathways along the surface and through the therapy site. Forexample, FIG. 21A depicts a surface impedance “Z_(surface)” along thetop surface of the skin 84 and a site impedance “Z_(site)” through thetherapy site 87. If “Z_(surface)” is significantly higher than“Z_(site)”, the magnitude of current “i₂” flowing through the “Z_(site)”path will be greater than the magnitude of current “i₁” flowing throughthe “Z_(surface)” path. The magnitudes of the surface impedance“Z_(surface)” and the site impedance “Z_(site)” can be adjusted by avariety of therapeutic parameters, including the distance between theelectrodes 402 and 406, the pressure applied to the electrodes 402 and406, the electrical stimulation parameters (e.g., frequency andmagnitude), and whether or not conductive gel is used at theelectrode-skin interfaces. For example, when the electrode tips 404 and408 are pressed into the skin 84 to depress the skin 84 in the regions86 a and 86 b (FIG. 21A), the tips 404 and 408 have an increased area ofcontact with the skin 84, which reduces the impedance “Z_(site)” betweenthe tips 404 and 408 and the therapy site 87 to drive more current “i₂”through the therapy site 87 relative to the current “i₁” transmittedalong the “Z_(surface)” path.

As indicated above, the magnitude of “Z_(surface)” can be adjusted bythe use of a conductive gel on the skin. FIG. 21C is a side view of aconfiguration in which a conductive gel 412 coats the surface of theskin 84 on which the first electrode 402 and the second electrode 406are placed. The conductive gel 412 improves the electrical contactbetween the tips 404 and 408 of the electrodes 402 and 406 at the skin84. Because the gel 412 is conductive, “Z_(surface)” is reduced relativeto the no-gel configuration, and an increased portion of the current “i”flows through the surface path. With conventional gels, “Z_(surface)”becomes so low relative to “Z_(site)” that very little of the current“i” is delivered to the therapy site 87. To increase the amount ofcurrent delivered to the therapy site 87, the electrodes 402 and 406 maybe positioned further apart or 4 4 may be prevented from beingsimultaneously in contact with the same gel.

Another way to address this situation is to adjust the conductivity ofthe gel 412 such that “Z_(surface)” is sufficiently high so that current“i” is delivered though the path of “Z_(site)” to the therapy site 87.The conductivity of the gel 412 may be adjusted by decreasing therelative portions of electrolytes and water in the gel, for example.Tuning the conductivity of the gel 412 may help achieve a more compactarrangement of the delivery electrode and the return electrode. Incertain implementations, the electrodes (e.g., the first electrode 402and the second electrode 406) are spaced approximately 1-10 mm apart. Incertain implementations, the edges of the electrodes (e.g., the firstelectrode 402 and the second electrode 406) are spaced approximately 3.5mm apart and the centers of the electrodes are spaced approximately 5millimeters apart. The electrodes (e.g., the first electrode 402 and thesecond electrode 406) may have any appropriate spacing as determined foreffective electrical stimulation therapy. In certain approaches, firstelectrode 402 and second electrode 406 are concentric electrodes (e.g.,as discussed above with reference to FIG. 19).

FIG. 22A is a side view of an electrode 418 with an integral conductivegel layer 420 disposed around the tip 419 of the electrode 418. The gellayer 420 is a gel-like solid that is soft, deformable, andsubstantially conductive, and may be permanently adhered to theelectrode tip 419. As depicted in FIG. 22B, when the electrode 418 isplaced on the surface of the skin 84, the gel layer 420 conforms to thesurface of the skin 84, both depressing the skin 84 in the region 86 andforming a conductive interface between the electrode 418 and thedepressed skin region 86. Examples of appropriate materials for the gellayer 420 include silicones, hydrogels, polysaccharides, and otherpolymers, such as polyvinylpyrollidone, polyethylene oxide, polyvinylalcohol, polyethylene glycol, polyacrylamide. The gel layer 420increases the conductivity of the skin-electrode interface, fillscontact voids to provide more uniform electrical contact, reduces skinirritation, and provides good electrical coupling. The gel layer 420 mayreduce or eliminate the need to apply conductive gels separately to theskin of the patient for the successful delivery of electricalstimulation therapy.

As depicted in FIG. 22C, the gel layer 420 also allows placement ofelectrodes near each other (e.g., approximately 1-10 mm apart) withoutcontacting each other or a common conductive gel along the surface ofthe skin. The gel layer 420 a of the electrode 418 a contacts the skinat the depressed region 86 a, but does not contact the gel layer 420 bof the second electrode 418 b. The electrodes 418 a and 418 b canthereby be placed close to each other to provide compact placement ofthe electrodes without significantly reducing the surface impedance“Z_(surface)”, thereby ensuring that the delivery of stimulation current“i” results in a sufficient, consistent, controlled current “ ” 2delivered to the therapy site 87 through the “Z_(site)” pathway (e.g.,“i₂” as described in relation to FIG. 21B). In certain approaches,electrodes 418 a and 418 b are concentric electrodes (e.g., as discussedabove with reference to FIG. 19).

Closely spaced electrodes (e.g., approximately 1-10 mm apart), such asthose depicted in FIGS. 21A, 21C, and 22C may provide improvedelectrical stimulation therapy and identification of therapy sites. Inpractice, a user (e.g., a care provider or a patient) can place theelectrodes 1 of the device 100 on the skin and easily move the electrodeover the skin to find an effective therapy site for applying electricalstimulation. For example, the patient may experience reduced pain whenthe electrodes are in certain positions, but have no such effect whenthe electrodes are located in other positions or. In the case ofstimulating muscle tissue or nerve connected to muscle tissue, thestimulation current may cause a muscle twitch when the electrodes are incertain positions, but have no such effect when the electrodes areoriented in other positions.

The orientation of the electrodes and resultant current paths inrelation to features of a patient's tissue may influence the efficacy ofthe stimulation therapy. FIGS. 23A and 23B depict the placement ofnon-invasive electrodes relative to a nerve. In FIG. 23A, a firstelectrode 804 and a second electrode 806 are spaced closely together(e.g., approximately 1-5 millimeters apart) and placed on the skin (notshown) along and in close proximity to a nerve 802 (which may be similarto nerve paths 90 a and 90 b of FIG. 1B). The first electrode 804 andthe second electrode 806 may be similar to the previously describedelectrodes 130, 402, 406, and 418. The placement of the electrodes 804and 806 relative to the nerve 802 forms a conductive current path 808approximately parallel to and along the nerve 802. When an electricalstimulation wave is applied across the electrodes 804 and 806, currentflows between the electrodes 804 and 806 along the current path 808,which causes movement of ions between the electrodes 804 and 806. 8 Themovement of ions in close proximity to the nerve 802 initiatesdepolarization of the nerve 802, which propagates along the nerve 802resulting in effective “in phase” stimulation. The user may thenidentify a response or effect of the electrical wave, such as reducedpain or a muscle movement.

FIG. 23B depicts placement of the electrodes 804 and 806 on either sideof the nerve 802, which results in a conductive current path 810 acrossor transverse to the nerve 802. In certain implementations, as shown inFIG. 23B, the electrodes 804 and 806 are spaced away from the nerve 802.When an electrical stimulation wave is applied, current flows betweenthe electrodes 804 and 806, however, due to the position of theelectrodes 804 and 806 away from the nerve 802, fewer ions move in theimmediate close proximity of the nerve 802. Accordingly, the nerve 802is insufficiently depolarized to cause propagation along the nerve 802,therefore the stimulation therapy is ineffective or “out of phase.” Theuser may then identify a response or effect of the electrical wave, suchas continued pain or lack of muscle movement.

With conventional electrode systems, therapy sites are grosslyapproximated. In order to compensate for the lack of precision withconventional systems, the stimulation current is typically increasedwhen the therapy is not effective. For example, a user may place anelectrode several millimeters from a therapy site, find that thestimulation therapy is not effective, and apply higher currents.Sufficiently high currents may depolarize a nerve, even when theelectrodes are in an “out of phase” orientation, but high currents mayresult in potential side effects, such as discomfort, skin irritation,tissue damage, or burns. High currents also require increased powerusage. The systems and methods described herein provide improvedaccuracy for placing electrodes for more effective, consistent treatmentwith potentially lower power usage. These systems and methods may beespecially useful for treatments requiring high levels of precision,such as along a nerve path for treating migraines or facial paralysis(e.g., Bell's palsy).

In practice, a user may rotate a pair of closely spaced electrodes (e.g.1-10 mm separation) to accurately identify a therapy site (e.g., therapysite 87) with millimeter precision. The user may find the stimulationeffective or “in phase” when the electrodes are in a first position(e.g., along the nerve as depicted in FIG. 23A). The user may rotate theelectrodes orientation by approximately 90° to a second position (e.g.,straddling the neve as depicted in FIG. 23B), resulting in “out ofphase” stimulation. In certain approaches, the user may rotate or spinthe electrodes along the surface of the skin, for example, slowlyrotating the electrodes in a circle to identify effective andineffective placements and orientations for the electrodes. In certainapproaches, a user may mark a therapy site and orientation with amarking element, such as a pen or marker tip, which in certainembodiments, is incorporated with the systems and methods describedherein.

The devices, systems and methods disclosed herein can also beimplemented in combination with kits with other electrical stimulationdevices. For example, the device described herein can be configured withan adapter that connects with TENS or other electrical stimulationdevices (e.g., with the connector and shoe used in the EMPI ActiveProduct sold by DJO through its subsidiary, EMPI Corp.). For example,FIGS. 24A and 24B depict a non-invasive electrical stimulation system500. The system 500 includes a rigid housing 516, a conductive portionhaving a rigid shaft 504 and a conductive tip 530, and a plastic orother rigid connector “shoe” 502 that joins the conductive portion tothe housing 516. Specifically, the shoe 502 has a proximal end 516 thatseats within a controller 520 when the controller 520 is mounted in theshoe 502 as depicted in FIG. 24B, forming an electrical-mechanicalinterface with the controller 520. The shoe 502 has a distal end 512that joins with the shaft 504 from which the electrode 530 extends. Anintermediate platform 514 (preferably made of a plastic) alsofacilitates alignment and mechanical connection of the shoe 502 to thecontroller 520. The connection between the shaft 504 and the shoe 502seats the shaft 504 in contact with conductive paths, such as wiring,within the shoe 502 that allows current to flow from the controller 520through the electrode 530. The conductive electrode 530 includes anarrow shaft 533 and a ball or other small contact surface 531, similarto the electrode 130 described above with reference to FIG. 2. Two sidefins 506 a and 506 b are also provided for device stability andhandling. An example of a controller and shoe that could be remodeledfor use in this system are disclosed in U.S. Patent ApplicationPublication No. 2009/0182393 and U.S. Patent Application Publication No.2009/0182394, both by Bachinski and titled SYSTEMS AND METHODS FORTHERAPEUTIC ELECTRICAL STIMULATION, the contacts of which are herebyincorporated by reference in their entireties.

FIG. 25 depicts an embodiment of an electrical stimulation therapysystem 700 that may be coupled to the head. System 700 may be useful toallow hands-free electrical stimulation therapy. System 700 may also beuseful for applying therapeutic electrical stimulation in the form ofinterferential stimulation. Interferential electrical stimulation usesat least two higher frequency signals, for example, frequencies between3500-4500 Hz, although any appropriate frequency may be used. Higherfrequency electrical signals penetrate tissue more readily than lowerfrequency electrical signals. In interferential stimulation, the signalshave different frequencies and therefore interfere constructively anddestructively in the tissue to form an interference wave or “beat wave”to stimulate the nerve or muscle tissue. The beat wave has a componentwith a lower frequency than the two original signals (which may havefrequencies between approximately 3500 Hz and 4500 Hz, for example).Lower frequency signals do not penetrate tissue as readily as higherfrequency signals, but are considered to stimulate nerve or muscletissue more effectively than higher frequency signals. Accordingly,interferential stimulation provides the benefits of using high frequencysignals to penetrate tissue and using low frequency signals to stimulatetissue. Interferential stimulation is described in further detail belowin relation to FIG. 26B.

The system 700 includes an electrode support 702 and an electrode patch710. The electrode support 702 includes a first electrode 706 and asecond electrode 708 in electrical communication with a stimulationdevice 704 via a signal line 722. In certain approaches, the electrodesupport 702 is configured to wrap around the head 80 of a patient. Forexample, the electrode support 702 may be a band, as depicted in FIG.25. Additionally or alternatively, the electrode support 702 may takethe form of a hat or helmet. In certain embodiments, the electrodesupport 702 is adjustable, for example, to enable a comfortable fit on apatient's head. The electrode support 702 may be formed of an elasticmaterial, such as a fabric or polymer. In certain approaches, theelectrode support 702 is structured to couple to a portion of the headwithout wrapping around the head. For example the electrode support 702may be a patch. Additionally or alternatively, the electrode support 702may take the form of a cervical collar, and may include or be coupled tothe electrode patch 710.

The first electrode 706 and the second electrode 708 are positioned onthe electrode support 702 and thereby coupled to patient's head 80. Incertain embodiments, the first electrode 706 and the second electrode708 are adjacently positioned in the electrode support 702 so that boththe first electrode 706 and second electrode 708 are positioned on theback of the head when the electrode support 702 is in use. In certainimplementations, the first electrode 706 and the second electrode 708are spaced between approximately 1 mm and approximately 150 mm apart.Although FIG. 25 depicts two electrodes on the electrode support 702,any number of electrodes may be used. For example, the electrode support702 may include an array of three or more electrodes. The firstelectrode 706 and the second electrode 708 may be similar to theelectrode 130 (FIG. 2). In certain implementations, the first electrode706 and the second electrode 708 are depressible, for example, asdescribed in relation to FIGS. 9A-15B. Additionally or alternatively,the first electrode 706 and the second electrode 708 may be flat surfaceelectrodes. In certain implementations, the signal line 722 (whichcouples the first electrode 706 and the second electrode 708 tostimulation device 704) comprises a plurality of signal lines such thatthe first electrode 706 and the second electrode 708 are electricallyindependent. For example, the signal line 722 may include multiple wiresor may be a multiplex signal line.

The system 700 additionally includes a patch 710 with a third electrode712 and a fourth electrode 714 in electrical communication with thestimulation device 704 via the signal line 724. In certain approaches,the patch 710 is coupled to the electrode support 702. For example, thepatch 710 may be an extension of the electrode support 702. Additionallyor alternatively, the system 700 may take the form of a helmet or hatthat includes the electrodes 706, 708, 712, and 714. The third electrode712 and the fourth electrode 714 are positioned on the patch 710 and arestructured to couple to the patient's tissue, for example, near thepatient's neck 88 or shoulders. In certain implementations, the thirdelectrode 712 and the fourth electrode 714 are adjacently positioned sothat both the third electrode 712 and fourth electrode 714 arepositioned on the back of the head when the patch 710 is in use. Incertain implementations, the third electrode 712 and the fourthelectrode 714 are spaced between approximately 1 mm and approximately150 mm apart. Although FIG. 25 depicts two electrodes on the patch 710,any number of electrodes may be used. For example, the patch 710 mayinclude an array of three or more electrodes. The third electrode 712and the fourth electrode 714 may be similar to the electrode 130 (FIG.2). In certain implementations, the third electrode 712 and the fourthelectrode 714 are depressible, for example, as described in relation toFIGS. 9A-15B. Additionally or alternatively, the third electrode 712 andthe fourth electrode 714 may be flat surface electrodes. In certainembodiments, the signal line 724 (which couples the third electrode 712and the fourth electrode 714 to the stimulation device 704) comprises aplurality of signal lines such that the third electrode 712 and thefourth electrode 714 are electrically independent. For example, thesignal line 724 may include multiple wires or may be a multiplex signalline.

The stimulation device 704 includes a power source (such as a battery)and a controller with a signal generator (such as controller 622 with asignal generator 660 of FIG. 5B) for delivering electrical stimulationtherapy. The stimulation device 704 may further include additionalcomponents for using the system 700, such as the switches, buttons, anddisplays described previously. In certain approaches, the stimulationdevice 704 is a handheld device. In alternative embodiments, thestimulation device 704 is integrated with the electrode support 702 orthe patch 710. For example, the system 700 may include a headband, hat,helmet, or patch that includes the stimulation device 704.

The electrode support 702 is placed around the head 80 of the patientwith the electrodes 706 and 708 at the back of the head 80. The patch710 is placed with the electrodes 712 and 714 on the neck 88. The patch710 may include an adhesive surface for coupling to the neck 88 or othertissue. In practice, the first electrode 706 is electrically coupledwith fourth electrode 714. As shown in FIG. 25, a first electricalstimulation signal is applied such that current “i₄” flows along theconductive path 718 through the therapy site 87. In certainimplementations, the first electrical signal is a periodic waveform witha frequency of approximately 3500-4500 Hz, although any appropriatefrequency may be used. For example, the first electrical signal may havea fixed frequency of 4000 Hz. In certain implementations, the frequencyof the first electrical signal is adjustable. For example, a user maymanually adjust the frequency of the first electrical signal with anactuation switch, such as a thumbwheel. In certain implementations, 6the stimulation device 704 is programmed to adjust the frequency of thefirst electrical signal automatically. For example, the stimulationdevice may automatically sweep the frequency at which stimulationcurrent is delivered. The sweep may be interrupted and frozen when apatient presses a designated button on the stimulation device 704, afterwhich point stimulation will continue to be delivered at the “frozen”frequency. Such a technique allows the patient to identify the frequencyat which he or she feels the most therapeutic effect and maintain thatfrequency throughout the treatment. In some implementations, the“frozen” frequency may be stored in a memory device for future therapysessions. In another example, the stimulation device may automaticallyvary the frequency of the electrostimulation to avoid thedesensitization of the patient's tissue that may occur when stimulationof a particular frequency is delivered in the same location for anextended period.

The second electrode 708 is electrically coupled with the thirdelectrode 712. As shown in FIG. 25, a second electrical stimulationsignal is applied such that current “i₃” flows along the conductive path716 through the therapy site 87. In certain implementations, the path716 and the path 718 intersect. In certain implementations, the secondelectrical signal is a periodic waveform with a frequency of betweenapproximately 3500Hz and approximately 4500 Hz, although any appropriatefrequency may be used. In practice, the frequency of the secondelectrical signal is different than the frequency of the firstelectrical signal. In certain approaches, the second electrical signalhas a frequency that is 1-200 Hz greater or less than the frequency ofthe first electrical signal. For example, the first electrical signalmay have a frequency of 4000 Hz and the second electrical signal mayhave a frequency of 4100 Hz. In certain implementations, the frequencyof the second electrical signal is adjustable. For example, a user maymanually adjust the frequency of the second electrical signal with anactuation switch, such as a thumbwheel. In certain implementations,tithe stimulation device 704 is programmed to adjust the frequency ofthe second electrical signal automatically.

When the first electrical signal and the second electrical signal areapplied, they interfere to form a lower frequency interferential signal(or “beat wave”) within the area 720. In certain implementations, theinterferential area 720 encompasses the therapy site 87. The resultinginterferential signal has a beat frequency equal to the difference inthe frequencies between the first and second electrical signals, asdescribed in further detail below. The lower frequency interferentialsignal stimulates the nerve or muscle tissue at the therapy site 87.

FIGS. 26A and 26B are diagrams of example electrical stimulationwaveforms that may be used for therapeutic electrical stimulation ofnerve or muscle tissue. FIG. 26A shows a generalized electricalstimulation waveform 802 generated by a signal generator of a controller(such as the signal generator 660 of the controller 622 of FIG. 5B). Thewaveform 802 of FIG. 26A is a biphasic square wave. In certainapproaches, the waveform 802 is a current waveform. Alternatively, thewaveform 802 may be a voltage waveform. The waveform 802 has a positivepulse 804 with an amplitude 806 and a pulse width 808. The waveform 802has an intrapulse interval 810 between the positive pulse 804 and anegative pulse 812. The negative pulse 812 has an amplitude 814 andpulse width 816. The negative pulse 812 is followed by an interpulseinterval 818, after which the stimulation pulses are repeated. Each ofthe pulse parameters (amplitude, width, intrapulse interval, interpulseinterval, and shape) is configurable. In certain approaches, theintrapulse interval 810 is approximately zero. In certain approaches,the interpulse interval 818 is approximately zero. In certainimplementations, the waveform 802 is symmetrical and charge balanced(i.e., no net positive or negative charge) with a positive pulse 804having an amplitude 806 and width 808 equal and opposite to theamplitude 814 and width 816 of the negative pulse 812. In certainapproaches, the positive pulse 804 and negative pulse 812 have differentamplitudes, widths, or shapes, thereby forming an asymmetrical waveformor an unbalanced (i.e., net positive or negative charge) waveform. Forexample, a monophasic waveform may used, which includes only positivepulses or only negative pulses. In certain approaches, other waveformshapes may be used, including sinusoidal, triangular, stair-step, orother symmetrical or asymmetrical waveform shapes. Additionally, thefrequency of the waveform 802 may be changed by adjusting the intrapulseinterval, interpulse interval, or both.

In certain implementations, the electrical stimulation waveform used forelectrical stimulation, such as the waveform 802, is periodic with apulse width (e.g., the pulse widths 808 and 816) between about 1microsecond (μs) and about 700 μs. For example, in certain preferredimplementations for migraine treatment, the pulse width is between about350 μsand about 450 μs, and may be approximately 400 μs. The frequencymay be adjusted within a range as desired by the user, particularlybetween approximately 5 Hz and approximately 4500 Hz. In some cases, anelectrical stimulation waveform with a frequency of about 90 Hz isoutput, while in some cases an electrical stimulation waveform with afrequency closer to 4000-4200 Hz is output. The amplitude may varyaccording to the pulse width and frequency, for example, in a constantpower mode.

FIG. 26B depicts interferential electrical stimulation. As discussedabove, interferential electrical stimulation uses at least two higherfrequency electrical signals to penetrate tissue, which interfereconstructively and destructively to form a lower frequency beat wave tostimulate the nerve or muscle tissue. With interferential electricalstimulation, a first waveform 830 is applied between a first pair ofelectrodes, such as the first electrode 706 and the fourth electrode 714of the system 700 depicted in FIG. 25. In certain implementations, thefirst waveform 830 is periodic with a positive amplitude 832, a negativeamplitude 834, and a frequency of approximately 3500-4500 Hz, althoughany appropriate frequency may be used. For example, the first waveform830 may have a fixed frequency of 4000 Hz. A second waveform 840 isapplied between a second pair of electrodes, such as the secondelectrode 708 and the third electrode 712 of the system 700 depicted inFIG. 25. In certain implementations, the second waveform 840 is periodicwith a positive amplitude 842, a negative amplitude 844, and a frequencyof approximately 3500-4500 Hz, although any appropriate frequency may beused. In practice, the second waveform 840 has a frequency that is 1-200Hz greater or less than the frequency of the first waveform 830. Forexample, if the first electrical signal has a frequency of 4000 Hz, thesecond electrical signal may have a frequency of 4100 Hz. In certainembodiments, the frequency of the second electrical signal isadjustable. For example, a user may manually adjust the frequency of thesecond electrical signal with an actuation switch. In certainimplementations, controller 622 is programmed to adjust the frequency ofthe second electrical signal automatically.

When the first electrical waveform 830 and the second electricalwaveform 840 interact in the same area (e.g., interferential area 720 ofFIG. 25), they interact both constructively and destructively to form aninterferential waveform 850. The interferential waveform 850 is alsoperiodic, as shown by beat wave 856, with a maximum positive amplitude852 and a maximum negative amplitude 854. The beat wave 856 has a beatfrequency equal to the difference in the frequencies between the firstelectrical waveform 830 and the second electrical waveform 840. Forexample, when the first electrical waveform 830 has a frequency of 4000Hz and the second electrical waveform 840 has a frequency of 4100 Hz,then beat wave 856 has a beat frequency of 100 Hz. The interferentialwaveform 850, with lower frequency beat wave 856, effectively stimulatesthe tissue. In certain implementations, for example, when only twoelectrodes are used, the interferential waveform 850 is produceddirectly by controller 622, instead of through interference of twowaveforms.

FIG. 27 is a block diagram of electronic components of an electricalstimulation therapy system 900 in accordance with the devices, systemsand methods described herein. The system 900, which may be similar to orinclude the device 100 (FIG. 2) or the system 200 (FIG. 6), includes apower supply 902, a battery 904, a controller 906, a power switch 908,amplitude adjustment switches 910, a data communication device 912, adata storage device 914, a switch 916, an output stage 918, an output920, and a return stage 936.

During normal operation, the power supply 902 receives power from thebattery 904. The battery 904 may be a lithium-ion battery having avoltage of about 3.7 to 4.2 volts, although other battery types andvoltages are used in some implementations. The power supply 902 convertsthe battery power to a desired voltage before supplying the power toother components of the system 900. For example, the power supply 902may include a step up converter to adjust or increase the voltage ofpower from the battery 904 to a desired voltage. The power supply 902also includes a battery charger 930. The battery charger 930 receivespower from an external power supply 940 and operates to recharge thebattery 904. In some implementations, the external power supply 940 is ahome or commercial power supply, such as those available through anelectrical power outlet or computer port (e.g., USB). In someimplementations, the external power supply 940 is a vehicle powersupply, such as a supply accessible through a 12V receptacle. Thebattery charger 930 may monitor the charge level of the battery 904 (forexample, with a thermistor to detect battery temperature). The batterycharger 930 may also provide an indicator of the charge level of thebattery 904.

The controller 906 is powered by the power supply 902 and controls theoperation of the system 900. In particular, the controller 906 generateselectrical signals that are provided to the output stage 918. Thecontroller 906 may be similar to or embody the controller 622 describedabove (e.g., with reference to FIG. 8). The controller 906 includes aprocessor 922 (which may be similar to or embody the processor 650 ofFIG. 8), which processes the input for the therapy (including thestimulation parameters) and communicates with the signal generator 924.The signal generator 924 (which may be similar to or embody the signalgenerator 660 of FIG. 8) receives an input from the processor 906 andgenerates a corresponding electrical stimulation waveform that istransferred to the output stage 918 for delivery to the therapy site920.

The controller 906 is electrically coupled to a power switch 908 andamplitude adjustment switches 910. These switches may be similar to orembody the switches underlying the buttons 908 a and 908 b of FIG. 2.The controller 906 monitors the state of the power switch 908. When thecontroller 906 detects that the state of the power switch 908 haschanged, the controller 906 turns the system 900 ON or OFF accordingly.The controller 906 also monitors the state of the amplitude adjustmentswitches 910. When the controller 906 detects that the state of theamplitude adjustment switches 910 has changed, the controller 906increases or decreases the intensity of electrical signals provided tothe output stage 918 accordingly. In certain embodiments, the amplitudeadjustment switches 910 are potentiometers. When one or more of thepotentiometers is adjusted, the intensity of the electrical signalgenerated by the signal generator 924 is increased or decreasedaccordingly.

The controller 906 includes a memory 932. Firmware 934 is stored in thememory 932. The firmware 934 includes software commands and algorithmsthat are executed by the controller 906 and defines logical operationsperformed by the controller 906. The software commands and algorithms inthe firmware 932 may be used to operate the electrical stimulationdevice in a desired mode, such as a mode that provides transcutaneouselectrical nerve stimulation therapy to the occipital nerve. Thecontroller 906 may use the memory 932 for storing statistics regardingusage of the system 900. For example, information such as type ofprogram, date and frequency of treatments, and intensities applied maybe recorded in the memory 932.

Usage statistics may be uploadable from the memory 932 to a data storage914. The data storage device 914 is a device capable of storing data,such as a memory card or other known data storage device. In someimplementations, the data storage device 914 is part of the memory 932.In certain implementations, current and historical operating parametersand physiological parameters (such as heart rate) are stored on the datastorage device 914 and can be accessed by a user.

Usage statistics may also be uploadable to a remote data source via thedata communication device 912. The data communication device 912 mayinclude one or more wired or wireless communication devices, such asserial bus communication devices (e.g., a Universal Serial Buscommunication devices), local area networking communication devices(e.g., an Ethernet communication device), a modem, a wireless areanetworking communication device (e.g., an 802.11x communication device),a wireless personal area networking device (e.g., a Bluetooth™communication device), or other communication device. The datacommunication device 912 can be used to send data to and receive datafrom another device. For example, the data communication device 912 canbe used to download different firmware 934 to the system 900 to alterthe operation of the controller 906, and operate the therapeuticelectrical stimulation device in a desired mode, such as a mode thatprovides electrical stimulation or iontophoresis therapy. In certainimplementations, a firmware algorithm must be purchased before it can bedownloaded by a user. In certain embodiments, a user must access a userinterface of a web server or other similar interface before downloadinga firmware algorithm. The data communication device 912 can also be usedto upload data to another device. For example, the controller 906 maystore a therapy log in the data storage device 914. The controlprocessor 906 can be used to upload the therapy log to an externaldevice by transmitting the data log via the data communication device912.

When the system 900 is ON, the controller 906 generates therapeuticelectrical signals, and provides those signals through the output stage918 to the therapy site 920. The switch 916 opens and closes theelectrical coupling between the controller 906 and the output stage 918.The output stage 918 is electrically coupled to an electrode (e.g.,electrodes 130, 230, or 330 as described above) that contacts thetherapy site 920 to deliver electrical signals to the patient. Incertain implementations, as described above, the switch 916 is apressure-activated switch that closes only when sufficient pressure isapplied to an electrode at the output stage 918, thereby forming acontinuous electrical path between the controller 906 and the outputstage 918. After delivery to the therapy site 920, the electrical signalflows through the return stage 936 back to the controller 906. Thereturn stage 936 is an electrical conductor (e.g., the conductivesurfaces 160 of FIG. 2 or the extension electrode 202 of FIG. 6) thatcontacts the patient to form a complete, continuous conductive paththrough the therapy site 920 back to the controller 906.

FIG. 28 is a block diagram of an exemplary system 1450 for communicatingbetween therapeutic electrical stimulation devices across acommunication network 1400. The system includes devices 100, 1402, and1404. The device 100 is in data communication with a docking station1300. The device 1404 includes a wireless communication device 1405 incommunication with a wireless router 1416. The device 1402 includes awired network communication device 1403. The system also includes aserver 1406, a caregiver computing system 1408, and a patient computingsystem 1410. The server 1406 includes a database 1412 and a Web server1414. The system 1450 also includes a wireless router 1416.

The communication network 1400 is a data communication network thatcommunicates data signals between devices. In this example, thecommunication network 1400 is in data communication with the dockingstation 1300, the device 1402, the device 1404, the server 1406, thecaregiver computing system 1408, the patient computing system 1410, andthe wireless router 1416. Examples of networks that may be included inthe communication network 1400 include the Internet, one or more localarea networks, one or more intranets, one or more near-field networks,one or more peer-to-peer networks, one or more ad hoc networks, andother communication networks.

In some implementations, the devices 100, 1402, and 1404 store, inmemory (not shown), data relating to therapy delivery or otheroperational characteristics of the respective devices. The communicationnetwork 1400 can be used to communicate that data to another device. Forexample, the data from one of the devices 100, 1402 or 1404 may betransferred to the patient computing system 1410 or to the caregivercomputing system 1408. Once the data has been transferred to the desiredcomputing system, the data is stored for review and analysis by thepatient or the caregiver.

The communication network 1400 can also be used to communicate data fromthe devices 100, 1402, and 1404 to the server 1406. The server 1406stores the data in a patient record database 1420. In someimplementations, the server 1406 includes a Web server 1414. The Webserver 1414 includes a caregiver interface 1430 and a patient interface1432. Additional interfaces are provided in some embodiments to thirdparties, such as an insurance company. The Web server 1414 generates webpages that are communicated across the communication network 1400 usinga standard communication protocol. An example of such a protocol ishypertext transfer protocol. The web page data is arranged in a standardform, such as hypertext markup language. The web page data istransferred across the communication network 1400 and received by thecaregiver computing system 1408, the patient computing system 1410, orboth. Browsers operating on the respective computing systems read theweb page data and display the web page to the user.

The caregiver interface 1430 generates a web page intended for use by acaregiver. The caregiver interface 1430 allows the caregiver to accessthe patient records database 1420 and generates reports or graphs toassist the caregiver in analyzing data from the patient records database1420. In addition, the caregiver interface 1430 provides technical ormedical suggestions to the caregiver. In some embodiments, the caregiverinterface 1430 also allows the caregiver to request adjustments to anoperational mode of a therapeutic electrical stimulation device (such asthe devices 100, 1402, and 1404). The operational mode adjustments arethen communicated from the server 1406 to the appropriate device, andthe device makes the appropriate mode adjustments.

The patient interface 1432 generates a web page intended for use by apatient. In some implementations, the patient interface 1432 allows thepatient to access the patient records database 1420 and generate reportsor graphs that assist the patient in analyzing data from the patientrecords database 1420. The patient interface 1432 may provideinstructions to assist the patient with uploading data from any of thedevices 100, 1402, and 1404 to the patient records database 1420. Otherinstructions or educational information may be provided by the patientinterface 1432, if desired.

In some implementations, the database 1412 includes a firmwarerepository 1422 firmware repository 1422 includes data instructions thatdefine the logical operation of a controller for a therapeuticelectrical stimulation device of the system 1450. An example of suchfirmware instructions is the firmware 934 of FIG. 24. The firmwarerepository 1422 is used in some implementations to store variousversions of firmware. For example, when a new firmware version iscreated, the developer stores the new version of firmware in thefirmware repository 1422. The firmware is then communicated to thedevices 100, 1402 and 1404 as appropriate. New firmware Versions can beautomatically distributed to the devices 100, 1402 and 1404, or providedas an option to a patient or caregiver through interfaces 1432 and 1422,respectively. In some embodiments, the patient interface 1432 requiresthat a patient agree to pay for an upgraded firmware version before thefirmware is made available for installation on a device.

In another embodiment, the firmware repository 1422 includes differentfirmware algorithms. Each firmware algorithm is specifically tailored toprovide a specific therapy when executed by devices 100, 1402 and 1404,or is tailored to be used with a particular hardware configuration.Examples of therapies defined by separate firmware algorithms includemigraine therapy, TENS, interferential therapy, edema therapy, musclestimulation, nerve stimulation, iontophoresis therapy, and othertherapies. A different firmware algorithm can also be specificallytailored for particular hardware configurations, such as for particularelectrode numbers or configurations, for particular data communicationdevices, for different docking stations, or to accommodate otherdifferences in hardware configuration.

For example, a patient may first obtain an electrical stimulationdevice, such as the device 100. The device includes a first firmwaretype that defines an algorithm appropriate for migraine therapy. Later,the patient desires to upgrade the device to cause the device to operateas an iontophoresis therapy device. To do so, the patient uses thepatient computing system 1410 to access the patient interface 1432. Thepatient selects a new firmware algorithm that is designed foriontophoresis therapy. The patient purchases and downloads the firmwareassociated with the iontophoresis therapy and loads the firmware ontothe device. If necessary, an appropriate electrode can be purchasedthrough the patient interface 1432 and delivered to the patient. Theelectrode is then connected to the device and the new firmware algorithmis executed. The firmware causes the device to provide the desirediontophoresis therapy. In this way, some implementations of theelectrical stimulation devices described herein are customizable toprovide multiple different therapies.

In some implementations, firmware is specially tailored for providing atherapy to a particular part of the body. As a result, differentfirmware algorithms are available for the treatment of different bodyparts and conditions associated with those body parts. Such firmwarealgorithms can be obtained by downloaded, as described above.

In certain approaches, the electrical stimulation devices and systemsdescribed herein are configured to deliver conductive gel when pressedagainst the tissue of a patient. FIG. 29 depicts a cross-sectional viewof a non-invasive electrical stimulation device with an integratedsystem for delivery of a conductive gel. A device with integrated geldelivery may enable the application of gel directly to the region of thetherapy site where the electrode is placed and therefore reduce oreliminate the need to apply gel with a separate device or operation. Byapplying gel directly to the region of the therapy site, the amount ofgel delivered may be reduced from conventional devices, which may beparticularly helpful, for example, when applying stimulation to atherapy site with hair, such as the back of the head. The device 1000includes an outer housing 1002, a contact surface 1004 disposed within asocket 1006, and a chamber 1018 that contains a conductive gel 1014 andis in fluid communication with the contact surface 1004. The chamber1018 can be used to retain and dispense a conductive gel to a patient'stissue (for example, to therapy site 87 as shown in FIG. 5A). In certainapproaches, the contact surface 1004 allows current to flow through anexposed portion 1024 of the contact surface 1004 to the patient'stissue. In certain approaches, the contact surface 1004 is an electrode.In certain approaches, the contact surface 1004 is a spherical shape.For example, the contact surface 1004 may be a metallic or conductivepolymer ball electrode (“rollerball electrode”) formed from chrome,silver-plated aluminum, stainless steel, silver chloride, or anysuitable conductive material. Additionally or alternatively, the contactsurface 1004 may be structured to allow current to flow through thecontact surface 1004, but may not be formed of a conductive material.For example, the contact surface 1004 may include pores or apertureswhich may contain a conductive material (e.g., a conductive gel) throughwhich current can flow. In certain approaches, the contact surface 1004is a sponge. In certain approaches, the device 1000 includes a pluralityof contact surfaces 1004. In certain approaches, the contact surface1004 is repositionable, for example, as described in relation to FIGS.9A-15B, such that the contact surface 1004 is repositioned to be inelectrical communication with a signal generator and deliver currentonly when sufficient pressure is applied to the contact surface 1004.

The contact surface 1004 is held within the socket 1006 between an outerlip 1010 and an inner collar 1012. The outer lip 1010 forms an outeropening 1028 through which the exposed portion 1024 of the contactsurface 1004 extends such that the exposed portion 1024 can contact thepatient during use. The inner collar 1012 forms an inner opening 1026.The outer opening 1028 and the inner opening 1026 are narrower than thecontact surface 1004 such that the contact surface 1004 is positionedwithin the socket 1006. In certain approaches, the contact surface 1004is loosely positioned within the socket 1006 such that a spacing 1022 ispresent between the contact surface 1004 and an inner wall 1008 of thesocket 1006. In such approaches, contact surface 1004 may roll or rotatewithin the socket 1006. In certain approaches, the socket 1006 isrepositionable within the housing 1002, thereby making the contactsurface 1004 repositionable. For example, as described in relation toFIGS. 9A-15B, the current may flow through the contact surface 1004 onlywhen sufficient pressure is applied to the contact surface 1004, suchthat the contact surface 1004 is repositioned to be in electricalcommunication with a signal generator.

The chamber 1018 serves as a reservoir for holding and dispensing theconductive gel 1014. The gel 1014 can flow through the inner opening1026 such that the conductive gel 1014 is in contact with the contactsurface 1004. In certain approaches, as the contact surface 1004 rotateswithin the socket 1006, the conductive gel 1014 adheres to the contactsurface 1004 to form a coating of the conductive gel 1014 on the contactsurface 1004, which gel can be delivered to the tissue of a patient fromthe exposed portion 1024 of the contact surface 1004. In certainapproaches (for example, when the contact surface 1004 includes pores),the conductive gel 1014 can flow through the contact surface 1004 to thetissue of a patient. In certain approaches, the housing 1002 includes anaperture so that as gel 1014 is delivered, air can flow into the chamber1018 to maintain a normal pressure equilibrium and prevent formation ofreduced pressure or a vacuum within the chamber. The aperture mayinclude a scrim, which is permeable to air or gas, but impermeable tothe gel 1014. In certain approaches, gel 1014 includes a therapeuticagent. For example, gel 1014 may include a molecule or drug for deliverythrough the skin during stimulation or iontophoresis therapy.

In certain implementations, the device 1000 is configured to deliverelectrical stimulation therapy. The device 1000 includes a conductor1016 positioned within the chamber 1018 and in electrical communicationwith the conductive gel 1014. For example, the conductor 1016 may bepositioned within the conductive gel 1014. The conductor 1016 is formedof an electrically conductive material such as a metal or conductivepolymer (e.g., chrome, silver-plated aluminum, silver chloride,stainless steel, or any suitable conductive material). In certainapproaches, the conductor 1016 is a rod. In certain approaches, theconductor 1016 is a wire. In certain approaches, the conductor 1016 isintegrated with the outer housing 1002. For example, the conductor 1016may be an inner surface, such as an inner wall, of the chamber 1018within the outer housing 1002. Since the gel 1014 is conductive, theconductive gel 1014 forms an electrically conductive pathway from theconductor 1016 to the contact surface 1004. In certain approaches, anintermediary conductive material is provided to electrically connect theconductor 1016 to the contact surface 1004. For example, theintermediary conductive material may be placed in the inner opening 1026to contact both the conductor 1016 and the contact surface 1004. Anintermediary conductive material may reduce the electrical impedance ofthe current path between the conductor 1016 and the contact surface 1004to reduce power consumption and enable more stable electricalstimulation. The intermediary conductive material may be a conductivepolymer, wire, fiber, or mesh. For example, the intermediary conductivematerial may be steel wool, stainless steel wool, copper wool, bronzewool, or any other suitable conductive material or polymer.

In certain approaches, the conductor 1016 is electrically connected to acable 1020. In certain approaches, the cable 1020 is electricallyconnected to a return electrode (not shown). In certain approaches, thecable 1020 is connected to a controller with a signal generator (forexample, the controller 622 with the signal generator 660 of FIG. 5B).In certain approaches, a controller and signal generator are integratedinto the device 1000 (e.g., as described above in relation to thestimulation device 100 and systems 200, 500, 700, and 900). When thecontroller of any of these devices or systems produces an electricalstimulation signal, the signal flows through the conductor 1016, thecontact surface 1004 and the conductive gel 1014 for delivery to atherapy site on the patient.

The device 1000 may be a consumable or disposable device, or may includeconsumable or disposable components. In certain approaches, the device1000 is used as a replaceable cartridge that is coupled within any ofthe stimulation devices and systems described herein, such as thestimulation device 100 and the systems 200, 500, 700, and 900. Forexample, the device 1000 may include a coupling structure, such as thethreads 1040, to couple the device 1000 to a housing or connector of astimulation device or system. In certain approaches the device 1000 isrepositionable within a housing of a stimulation device or system, forexample, as described in relation to FIGS. 9A-15B. For example, theconnection between the device 1000 and the housing of a stimulationdevice or system may include a compression spring. The device 1000 maybe removable and/or disposable so that when the gel 1014 is depleted,the device 1000 may be decoupled from an electrical stimulation deviceor system and replaced. In certain implementations, the device 1000 isrefillable, so that when the gel 1014 is depleted, a user may refill thedevice 1000 with the gel 1014. In certain approaches, the device 1000 isnot replaceable, removable, or refillable. In these approaches, when thegel 1014 is depleted, the device 1000 may be disposed of. The chamber1018 may be removable, disposable, or refillable (e.g., when the chamber1018 is fixedly coupled to the outer housing 1002). In certainimplementations, the device 1000 is integrated with the stimulationdevice 100 or systems 200, 500, 700, and 900, and when the gel 1014 isdepleted, the entire electrical stimulation device or system is disposedof in certain approaches, the threads 1040 may couple to a cap toprotect the contact surface 1004 and prevent the gel 1014 from drying.

FIG. 30 depicts the device 1000 as applied to a patient. In use, thepatient positions the device 1000 on the skin 1032 near a target area1034, which receives the gel 1014 from the device 1000 from rolling thecontact surface 1004. Current flows from a signal generator (not shown)through the contact surface 1004 and into the target area 1034. Thecurrent then flows through the patient's tissue to the return electrode1030 and through the cable 1036 back to the signal generator. In certainapproaches, the return electrode 1030 is coupled to the housing of thedevice 1000 (e.g., as described, for example in relation to theconductive surface 160 of the device 100 of FIG. 2). In certainapproaches, the return electrode 1030 extends from the housing of thedevice 1000 or is positioned near contact surface 1004 (for example, asdescribed above in relation to FIGS. 16-23). The contact surface 1004 iscoated with the conductive gel 1014 to provide good electrical couplingfor electrical stimulation therapy. In certain approaches, as the usermoves the contact surface 1004 along the skin 1032, the contact surface1004 delivers the conductive gel 1014 to the target area 1034, Thedevice 1000 thereby allows the user to conveniently deliver stimulationtherapy with a conductive gel electrical interface, but eliminates theneeds to separately apply the gel. Although FIG. 30 is depicted fortreating a target area 1034 near or on a patient's hand, the systems andmethods described herein may be used to treat target areas located at ornear the occipital nerve, face, neck, shoulders, back, arms, legs, feet,or any other portion of the body.

FIG. 31 is a cross-sectional exploded view of a non-invasive electricalstimulation device for providing electrical stimulation therapy to thesurface of a patient, such as the back of the patient's head. The device1100 an upper portion 1102 with integrated electronics and a tip portion1104 with rollerball electrode 1144 for electrical stimulation anddelivery of a gel 1162 from a reservoir chamber 1148. The upper portion1102 and tip portion 1104 can be releasably connected. For example, incertain approaches, the housing 1106 of the upper portion 1102 includesthreads 1138, within which threads 1140 on the housing 1142 of the tipportion 1104 can connect by twisting. In certain approaches, the tipportion 1104 releasably connects to the upper portion 1102 by slidinginto the upper portion 1102 with a tight, friction fit. In alternativeimplementations, the tip portion 1104 may be connected to the upperportion 1102 by a clip, a snap fitting, glue, or another connectionmechanism, or may be integral with the housing 1106. The tip portion1104 may be consumable or disposable. In certain approaches, the tipportion 1104 is coupled to the upper portion 1102 such the tip portionis repositionable and forms an electrical connection only whensufficient pressure is applied to the electrode 1144.

The upper portion 1102 is in the form of a rigid shaft that houseselectronics, ports, buttons, and other elements. The housing 1106 ofupper portion 1102 may be substantially cylindrical. For example, thehousing 1106 may be shaped similar to a pen so that it can be heldeasily in the hand of a user. A printed circuit board (PCB) 1114 islocated within the body portion 1102 to position and connect theelectronic components. For example, a controller 1116 is mounted on PCB1114. The controller 1116 may include a signal generator. Examples ofdevices that may be used to implement the controller include, but arenot limited to, microprocessors, microcontrollers, integrated circuits(ICs), central processing units (CPUs), programmable logic devices,field programmable gate arrays, and digital signal processing (DSP)devices. A battery 1118 or other power source is also connected to thePCB 1114 and controller 1116, for example, with wire 1134 and wire 1136.The wires depicted throughout the embodiments are electricalcommunication pathways, and may be implemented in other forms, forexample, by traces on a PCB (e.g., PCB 1114) or wireless communicationmethods.

The upper portion 1102 includes buttons 1108 and 1110, which may be usedto turn the device on and off, increase and decrease the levels ofstimulation, and adjust other therapy settings (e.g., waveform shape,frequency). Buttons 1108 and 1110 are electrically connected tocontroller 1116, for example, with wires 1128 and 1130. In certainembodiments, one or both of the buttons 1108 and 1110 includepotentiometers. When the potentiometer is adjusted, the intensity of theelectrical stimulation signal provided by the device 1100 is increasedor decreased accordingly.

The upper portion 1102 includes an electrical port 1112 for receiving anelectrical connector to recharge the battery 1118 of the device 1100.Port 1112 is electrically connected to controller 1116, for example,with wire 1122 and wire 1124. In some implementations, the port 1112includes a thermistor to monitor the temperature of battery 1118 duringcharging to avoid overheating. In some such implementations, the chargelevel is indicated by a status indicator. In certain implementations, auser connects the device 1100 to bedside equipment via a connection withthe port 1112 (which may be, for example, a USB port), to download datafrom the device 1100 or upload data to the device 1100. In certainembodiments, port 1112 is used to download stimulation protocols orupdate firmware for the internal controller.

The upper portion 1102 may include a connector 1152 for connecting areturn electrode (not shown). Connector 1152 may be electricallyconnected to controller 1116, for example, with wire 1126. The returnelectrode may be an extension electrode, for example, as depicted byreturn electrode 202 in FIG. 6 and FIG. 7. In certain approaches,connector 1152 releasably attaches to the return electrode. Additionallyor alternatively, upper portion 1102 may include a return electrode onthe outside of the housing 1106, which would contact a user's hand whenthe user holds device 1100 to apply stimulation. For example, upperportion 1102 may include conductive contact surfaces similar toconductive surfaces 160 as depicted in FIG. 2, FIG. 3, FIG. 5A, FIG. 6,and FIG. 7.

In certain embodiments, upper portion 1102, includes a distal connector1120 for electrically connecting to the tip portion 1104. Distalconnector 1120 is electrically connected to controller 1116, forexample, with wire 1132. Distal connector 1120 connects to the proximalend 1156 of the conductor 1146 from the tip portion 1104 when the tipportion 1104 is coupled to the body portion 1102 (e.g., by screwing orsliding the tip portion 1104 into the body portion 1102 as describedabove). In certain approaches, connector 1120 includes a compressionspring, which applies pressure to the conductor 1146 to provide a stablemechanical and electrical connection. In certain approaches, connector1120 is a spring.

The device 1100 includes a tip portion 1104 with a rollerball electrode1144. When the tip portion 1104 is connected to the body portion 1102,the electrode 1144 is in electrical communication with the controller1116 and can deliver electrical stimulation. In certain approaches, theelectrode 1144 is repositionable and forms an electrical connection withthe controller 1116 only when sufficient pressure is applied to theelectrode 1144, for example, as described in relation to FIGS. 9A-15B.The electrode 1144 is in contact with an intermediary conductivematerial 1150 to form a stable electrical communication pathway from theelectrode 1144 to the conductor 1146. The intermediary conductivematerial 1150 may reduce the electrical impedance of the current pathbetween the conductor 1146 and the electrode 1144 to reduce powerconsumption and enable more stable electrical stimulation. Theintermediary conductive material 1150 may be a conductive polymer, wire,fiber, or mesh. For example, the intermediary conductive material 1150may be steel wool, stainless steel wool, copper wool, bronze wool, orany other suitable conductive material or polymer. The intermediaryconductive material 1150 is porous or fibrous so that the conductive gel1162 can flow from the chamber 1148 through the spaces within theintermediary conductive material 1150 to the electrode 1144 and to thepatient, as described above in relation to FIGS. 29.30. The conductor1146 is formed of an electrically conductive material such as a metal orconductive polymer (e.g., chrome, silver-plated aluminum, silverchloride, stainless steel, or any suitable conductive material). Incertain approaches, the conductor 1146 is a rod. In certain approaches,the conductor 1146 is a wire. In certain approaches, the conductor 1146is integrated with the housing 1142. For example, the conductor 1146 maybe an inner surface, such as an inner wall, of the chamber 1148 withinthe housing 1142.

The chamber 1148 serves as a reservoir for holding the conductive gel1162. The chamber 1148 includes a seal 1154 so that the gel 1162 iscontained within the chamber 1148 and does not leak out or onto theelectrical components. In certain approaches, the housing 1142 of thetip portion 1104 includes an aperture 1158 so that as gel 1162 isdelivered, air can flow into the chamber 1148 to maintain a normalpressure equilibrium and prevent formation of reduced pressure or avacuum within the chamber. The aperture may include a scrim 1160, whichis permeable to air or gas, but impermeable to the gel 1162. In certainembodiments, the seal 1154 is permeable to air or gas, but impermeableto the gel 1162 and maintains pressure equilibrium without the need foran additional aperture or scrim.

The devices and systems described herein can be used as diagnostic toolsto identify trigger points along the surface of a patient's skin. Theycan also be used to treat acute or localized pain arising, for example,from insect bites, pinched nerves or other conditions. Veterinarians maybe also find these devices and systems useful for treating animals.Other implementations may include the treatment of arthritis in apatient's hands and feet where electrode placement is difficult. In suchimplementations, a patient can operate the stimulation device with onehand and apply the device to the other hand. Other implementations ofthe device may include uses in dental applications or on other regionsof the body, with the components of the device contoured for specificregions. The devices and systems described herein may be particularlyadvantageous in facial and dermatology applications in which preciseelectrical stimulation is desired. For example, the devices and systemsdescribed herein may be used to treat facial paralysis, such as Bell'spalsy. The device may also be used as a pain assessment tool by thecaregiver or by the patient.

Variations and modifications will occur to those of skill in the artafter reviewing this disclosure. The disclosed features may beimplemented, in any combination and sub combinations (including multipledependent combinations and sub-combinations), with one or more otherfeatures described herein. The various features .described orillustrated above, including any components thereof, may be combined orintegrated in other systems. Moreover, certain features may be omittedor not implemented.

Examples of changes, substitutions, and alterations are ascertainable byone skilled in the art and could be made without departing from thescope of the information disclosed herein. All references cited hereinare incorporated by reference in their entirety and made part of thisapplication.

1. (canceled)
 2. A method of delivering electrical stimulation to apatient using a device comprising a housing, a conductive surfacedisposed on an outer surface of the housing, and an electrode that isrepositionable with respect to the housing, the method comprising: in aprogrammable processor disposed within the housing, generatingstimulation control signals based on waveform information received inthe processor; in a signal generator disposed within the housing,receiving the stimulation control signals and generating correspondingelectrical stimulation waveforms, the signal generator comprising afirst signal line and a second signal line; contacting a surface of theelectrode and the conductive surface to the patient, the conductivesurface in electrical communication with the first signal line of thesignal generator; moving the electrode between a first position that isnot in electrical communication with the second signal line and a secondposition that is in electrical communication with the second signalline; and transmitting the electrical stimulation waveforms through theelectrode to a nerve beneath the patient's skin when the electrode is inthe second position.
 3. The method of claim 2, wherein transmitting theelectrical stimulation waveforms comprises transmitting electricalstimulation waveforms having predetermined amplitudes and fixedfrequencies.
 4. The method of claim 2, further comprising varying theelectrical stimulation waveforms in response to waveform informationreceived in the processor.
 5. The method of claim 2, wherein thewaveform information includes at least one of frequency, amplitude,pulse width, pulse shape, and duration of the electrical stimulationwaveforms.
 6. The method of claim 2, further comprising receiving thewaveform information in the processor via a port in the outer surface ofthe housing.
 7. The method of claim 2, further comprising: using thewaveform information received in the processor, programming theprocessor to adjust the electrical stimulation waveforms over a specifictime according to a programmed schedule.
 8. The method of claim 2,wherein the waveform information received in the processor includesstimulation protocols in a prescribed treatment regimen, and wherein themethod further comprises: programming the processor to adjust theelectrical stimulation waveforms according to the prescribed treatmentregimen.
 9. The method of claim 2, further comprising programming theprocessor to output stimulation control signals that generate a first,low frequency electrical stimulation waveform followed by a second, highamplitude electrical stimulation waveform.
 10. The method of claim 2,further comprising transmitting the waveform information from anexternal source to the processor through a port in the outer surface ofthe housing.
 11. The method of claim 10, further comprising: using thewaveform information received in the processor through the port,programming the processor to adjust at least one characteristic of theelectrical stimulation waveforms.
 12. The method of claim 10, whereinthe processor receives the waveform information from a USB connectionthrough the port.
 13. The method of claim 2, further comprising:wirelessly receiving the waveform information in the processor from anexternal source; and using the waveform information, programming theprocessor to adjust at least one characteristic of the electricalstimulation waveforms.
 14. A method of treating a headache, comprising:positioning a first electrode on skin at a location near a patient'soccipital nerve; electrically coupling the first electrode to a secondelectrode; applying pressure to the first electrode, wherein the firstelectrode translates along an axis to complete an electricalcommunication path with a signal generator; and delivering currentthrough the first electrode to thereby stimulate the occipital nerve.15. The method of claim 14, wherein the first electrode is a conductivesurface extending from a housing, and wherein the method furthercomprises: in a programmable processor disposed within the housing,generating stimulation control signals based on stimulation protocolsreceived in the processor; in the signal generator disposed within thehousing: receiving the stimulation control signals, generatingcorresponding electrical stimulation waveforms, and delivering thecurrent through the first electrode in accordance with the electricalstimulation waveforms.
 16. The method of claim 15, further comprisingreceiving the stimulation protocols in the processor through a port inan exterior surface of the housing.
 17. The method of claim 16, whereinthe stimulation protocols received in the processor through the portprogram the processor to adjust at least one of frequency, amplitude,pulse width, pulse shape, and duration of the electrical stimulationwaveforms.
 18. The method of claim 14, further comprising adjusting thelevel of current delivered through the first electrode.
 19. The methodof claim 14, wherein applying pressure to translate the first electrodecloses a switch and delivers the current.
 20. The method of claim 14,further comprising positioning the second electrode on a portion of theskin of the patient.
 21. The method of claim 14, further comprisingapplying a conductive gel to the skin from a surface of the firstelectrode, wherein the first electrode is positioned within a housing,and wherein the conductive gel flows from a chamber within the housingto the first electrode and from the first electrode to the skin.